diff --git a/colour.c b/colour.c
index 88198e96..1cad01f9 100644
--- a/colour.c
+++ b/colour.c
@@ -120,6 +120,28 @@ colour_force_rgb(int c)
 	return (-1);
 }
 
+/* Dim colour by a percentage. */
+int
+colour_dim(int c, u_int dim)
+{
+	u_char	r, g, b;
+
+	if (dim == 0 || COLOUR_DEFAULT(c))
+		return (c);
+	if (dim >= 100)
+		return (colour_join_rgb(0, 0, 0));
+
+	c = colour_force_rgb(c);
+	if (c == -1)
+		return (-1);
+	colour_split_rgb(c, &r, &g, &b);
+
+	r = (r * (100 - dim)) / 100;
+	g = (g * (100 - dim)) / 100;
+	b = (b * (100 - dim)) / 100;
+	return (colour_join_rgb(r, g, b));
+}
+
 /* Convert colour to a string. */
 const char *
 colour_tostring(int c)
diff --git a/format.c b/format.c
index 06192962..0f09bb67 100644
--- a/format.c
+++ b/format.c
@@ -128,6 +128,9 @@ format_job_cmp(struct format_job *fj1, struct format_job *fj2)
 /* Limit on time taken (milliseconds). */
 #define FORMAT_TIME_LIMIT 100
 
+/* How often to check the time in long loops. */
+#define FORMAT_TIME_LOOP_CHECK 10000
+
 /* Format expand flags. */
 #define FORMAT_EXPAND_TIME 0x1
 #define FORMAT_EXPAND_NOJOBS 0x2
@@ -573,7 +576,7 @@ format_cb_session_attached_list(struct format_tree *ft)
 	}
 
 	if ((size = EVBUFFER_LENGTH(buffer)) != 0)
-		xasprintf(&value, "%.*s", size, EVBUFFER_DATA(buffer));
+		value = xmemdup(EVBUFFER_DATA(buffer), size);
 	evbuffer_free(buffer);
 	return (value);
 }
@@ -712,7 +715,7 @@ format_cb_window_linked_sessions_list(struct format_tree *ft)
 	}
 
 	if ((size = EVBUFFER_LENGTH(buffer)) != 0)
-		xasprintf(&value, "%.*s", size, EVBUFFER_DATA(buffer));
+		value = xmemdup(EVBUFFER_DATA(buffer), size);
 	evbuffer_free(buffer);
 	return (value);
 }
@@ -766,7 +769,7 @@ format_cb_window_active_sessions_list(struct format_tree *ft)
 	}
 
 	if ((size = EVBUFFER_LENGTH(buffer)) != 0)
-		xasprintf(&value, "%.*s", size, EVBUFFER_DATA(buffer));
+		value = xmemdup(EVBUFFER_DATA(buffer), size);
 	evbuffer_free(buffer);
 	return (value);
 }
@@ -830,7 +833,7 @@ format_cb_window_active_clients_list(struct format_tree *ft)
 	}
 
 	if ((size = EVBUFFER_LENGTH(buffer)) != 0)
-		xasprintf(&value, "%.*s", size, EVBUFFER_DATA(buffer));
+		value = xmemdup(EVBUFFER_DATA(buffer), size);
 	evbuffer_free(buffer);
 	return (value);
 }
@@ -1005,7 +1008,7 @@ format_cb_pane_tabs(struct format_tree *ft)
 		evbuffer_add_printf(buffer, "%u", i);
 	}
 	if ((size = EVBUFFER_LENGTH(buffer)) != 0)
-		xasprintf(&value, "%.*s", size, EVBUFFER_DATA(buffer));
+		value = xmemdup(EVBUFFER_DATA(buffer), size);
 	evbuffer_free(buffer);
 	return (value);
 }
@@ -1020,7 +1023,7 @@ format_cb_pane_fg(struct format_tree *ft)
 	if (wp == NULL)
 		return (NULL);
 
-	tty_default_colours(&gc, wp);
+	tty_default_colours(&gc, wp, NULL);
 	return (xstrdup(colour_tostring(gc.fg)));
 }
 
@@ -1057,7 +1060,7 @@ format_cb_pane_bg(struct format_tree *ft)
 	if (wp == NULL)
 		return (NULL);
 
-	tty_default_colours(&gc, wp);
+	tty_default_colours(&gc, wp, NULL);
 	return (xstrdup(colour_tostring(gc.bg)));
 }
 
@@ -1089,7 +1092,7 @@ format_cb_session_group_list(struct format_tree *ft)
 	}
 
 	if ((size = EVBUFFER_LENGTH(buffer)) != 0)
-		xasprintf(&value, "%.*s", size, EVBUFFER_DATA(buffer));
+		value = xmemdup(EVBUFFER_DATA(buffer), size);
 	evbuffer_free(buffer);
 	return (value);
 }
@@ -1129,7 +1132,7 @@ format_cb_session_group_attached_list(struct format_tree *ft)
 	}
 
 	if ((size = EVBUFFER_LENGTH(buffer)) != 0)
-		xasprintf(&value, "%.*s", size, EVBUFFER_DATA(buffer));
+		value = xmemdup(EVBUFFER_DATA(buffer), size);
 	evbuffer_free(buffer);
 	return (value);
 }
@@ -4254,10 +4257,14 @@ found:
 
 /* Check if format has not taken too long. */
 static int
-format_check_time(struct format_expand_state *es)
+format_check_time(struct format_expand_state *es, u_int *check)
 {
-	uint64_t t = get_timer();
+	uint64_t t;
 
+	if (check != NULL && ++*check % FORMAT_TIME_LOOP_CHECK != 0)
+		return (1);
+
+	t = get_timer();
 	if (t - es->start_time < FORMAT_TIME_LIMIT)
 		return (1);
 	t -= es->start_time;
@@ -4268,21 +4275,24 @@ format_check_time(struct format_expand_state *es)
 
 /* Unescape escaped characters. */
 static char *
-format_unescape(struct format_expand_state *es, const char *s)
+format_unescape(struct format_expand_state *es, const char *s, size_t n)
 {
-	char	*out, *cp;
-	int	 brackets = 0;
+	const char	*end = s + n;
+	char		*out, *cp;
+	int		 brackets = 0;
+	u_int		 check = 0;
 
-	cp = out = xmalloc(strlen(s) + 1);
-	for (; *s != '\0'; s++) {
-		if (!format_check_time(es)){
+	cp = out = xmalloc(n + 1);
+	for (; s != end; s++) {
+		if (!format_check_time(es, &check)) {
 			free(out);
 			return (xstrdup(""));
 		}
-		if (*s == '#' && s[1] == '{')
+		if (*s == '#' && s + 1 != end && s[1] == '{')
 			brackets++;
 		if (brackets == 0 &&
 		    *s == '#' &&
+		    s + 1 != end &&
 		    strchr(",#{}:", s[1]) != NULL) {
 			*cp++ = *++s;
 			continue;
@@ -4301,10 +4311,11 @@ format_strip(struct format_expand_state *es, const char *s)
 {
 	char	*out, *cp;
 	int	 brackets = 0;
+	u_int	 check = 0;
 
 	cp = out = xmalloc(strlen(s) + 1);
 	for (; *s != '\0'; s++) {
-		if (!format_check_time(es)){
+		if (!format_check_time(es, &check)) {
 			free(out);
 			return (xstrdup(""));
 		}
@@ -4328,9 +4339,10 @@ static const char *
 format_skip1(struct format_expand_state *es, const char *s, const char *end)
 {
 	int	brackets = 0;
+	u_int	check = 0;
 
 	for (; *s != '\0'; s++) {
-		if (es != NULL && !format_check_time(es))
+		if (es != NULL && !format_check_time(es, &check))
 			return (NULL);
 		if (*s == '#' && s[1] == '{')
 			brackets++;
@@ -4501,7 +4513,7 @@ format_build_modifiers(struct format_expand_state *es, const char **s,
 				break;
 
 			argv = xcalloc(1, sizeof *argv);
-			value = xstrndup(cp + 1, end - (cp + 1));
+			value = format_unescape(es, cp + 1, end - (cp + 1));
 			argv[0] = format_expand1(es, value);
 			free(value);
 			argc = 1;
@@ -4525,7 +4537,7 @@ format_build_modifiers(struct format_expand_state *es, const char **s,
 			cp++;
 
 			argv = xreallocarray(argv, argc + 1, sizeof *argv);
-			value = xstrndup(cp, end - cp);
+			value = format_unescape(es, cp, end - cp);
 			argv[argc++] = format_expand1(es, value);
 			free(value);
 
@@ -4688,7 +4700,8 @@ format_loop_sessions(struct format_expand_state *es, const char *fmt)
 	struct format_tree		 *nft;
 	struct format_expand_state	  next;
 	char				 *all, *active, *use, *expanded, *value;
-	size_t				  valuelen;
+	struct evbuffer			 *buffer;
+	size_t				  size;
 	struct session			 *s, **l;
 	int				  i, n, last = 0;
 
@@ -4697,8 +4710,9 @@ format_loop_sessions(struct format_expand_state *es, const char *fmt)
 		active = NULL;
 	}
 
-	value = xcalloc(1, 1);
-	valuelen = 1;
+	buffer = evbuffer_new();
+	if (buffer == NULL)
+		fatalx("out of memory");
 
 	l = sort_get_sessions(&n, sc);
 	for (i = 0; i < n; i++) {
@@ -4719,16 +4733,18 @@ format_loop_sessions(struct format_expand_state *es, const char *fmt)
 		expanded = format_expand1(&next, use);
 		format_free(next.ft);
 
-		valuelen += strlen(expanded);
-		value = xrealloc(value, valuelen);
-
-		strlcat(value, expanded, valuelen);
+		evbuffer_add(buffer, expanded, strlen(expanded));
 		free(expanded);
 	}
 
 	free(active);
 	free(all);
 
+	if ((size = EVBUFFER_LENGTH(buffer)) != 0)
+		value = xmemdup(EVBUFFER_DATA(buffer), size);
+	else
+		value = xstrdup("");
+	evbuffer_free(buffer);
 	return (value);
 }
 
@@ -4798,7 +4814,8 @@ format_loop_windows(struct format_expand_state *es, const char *fmt)
 	struct format_tree		 *nft;
 	struct format_expand_state	  next;
 	char				 *all, *active, *use, *expanded, *value;
-	size_t				  valuelen;
+	struct evbuffer			 *buffer;
+	size_t				  size;
 	struct winlink			 *wl, **l;
 	struct window			 *w;
 	int				  i, n, last = 0;
@@ -4813,8 +4830,9 @@ format_loop_windows(struct format_expand_state *es, const char *fmt)
 		active = NULL;
 	}
 
-	value = xcalloc(1, 1);
-	valuelen = 1;
+	buffer = evbuffer_new();
+	if (buffer == NULL)
+		fatalx("out of memory");
 
 	l = sort_get_winlinks_session(ft->s, &n, sc);
 	for (i = 0; i < n; i++) {
@@ -4846,16 +4864,18 @@ format_loop_windows(struct format_expand_state *es, const char *fmt)
 		expanded = format_expand1(&next, use);
 		format_free(nft);
 
-		valuelen += strlen(expanded);
-		value = xrealloc(value, valuelen);
-
-		strlcat(value, expanded, valuelen);
+		evbuffer_add(buffer, expanded, strlen(expanded));
 		free(expanded);
 	}
 
 	free(active);
 	free(all);
 
+	if ((size = EVBUFFER_LENGTH(buffer)) != 0)
+		value = xmemdup(EVBUFFER_DATA(buffer), size);
+	else
+		value = xstrdup("");
+	evbuffer_free(buffer);
 	return (value);
 }
 
@@ -4870,7 +4890,8 @@ format_loop_panes(struct format_expand_state *es, const char *fmt)
 	struct format_tree		*nft;
 	struct format_expand_state	 next;
 	char				*all, *active, *use, *expanded, *value;
-	size_t				 valuelen;
+	struct evbuffer			*buffer;
+	size_t				 size;
 	struct window_pane		*wp, **l;
 	int				  i, n, last = 0;
 
@@ -4884,8 +4905,9 @@ format_loop_panes(struct format_expand_state *es, const char *fmt)
 		active = NULL;
 	}
 
-	value = xcalloc(1, 1);
-	valuelen = 1;
+	buffer = evbuffer_new();
+	if (buffer == NULL)
+		fatalx("out of memory");
 
 	l = sort_get_panes_window(ft->w, &n, sc);
 	for (i = 0; i < n; i++) {
@@ -4905,16 +4927,18 @@ format_loop_panes(struct format_expand_state *es, const char *fmt)
 		expanded = format_expand1(&next, use);
 		format_free(nft);
 
-		valuelen += strlen(expanded);
-		value = xrealloc(value, valuelen);
-
-		strlcat(value, expanded, valuelen);
+		evbuffer_add(buffer, expanded, strlen(expanded));
 		free(expanded);
 	}
 
 	free(active);
 	free(all);
 
+	if ((size = EVBUFFER_LENGTH(buffer)) != 0)
+		value = xmemdup(EVBUFFER_DATA(buffer), size);
+	else
+		value = xstrdup("");
+	evbuffer_free(buffer);
 	return (value);
 }
 
@@ -4929,11 +4953,13 @@ format_loop_clients(struct format_expand_state *es, const char *fmt)
 	struct format_tree		 *nft;
 	struct format_expand_state	  next;
 	char				 *expanded, *value;
-	size_t				  valuelen;
+	struct evbuffer			 *buffer;
+	size_t				  size;
 	int				  i, n, last = 0;
 
-	value = xcalloc(1, 1);
-	valuelen = 1;
+	buffer = evbuffer_new();
+	if (buffer == NULL)
+		fatalx("out of memory");
 
 	l = sort_get_clients(&n, sc);
 	for (i = 0; i < n; i++) {
@@ -4948,13 +4974,15 @@ format_loop_clients(struct format_expand_state *es, const char *fmt)
 		expanded = format_expand1(&next, fmt);
 		format_free(nft);
 
-		valuelen += strlen(expanded);
-		value = xrealloc(value, valuelen);
-
-		strlcat(value, expanded, valuelen);
+		evbuffer_add(buffer, expanded, strlen(expanded));
 		free(expanded);
 	}
 
+	if ((size = EVBUFFER_LENGTH(buffer)) != 0)
+		value = xmemdup(EVBUFFER_DATA(buffer), size);
+	else
+		value = xstrdup("");
+	evbuffer_free(buffer);
 	return (value);
 }
 
@@ -5120,7 +5148,7 @@ format_replace(struct format_expand_state *es, const char *key, size_t keylen,
 	struct format_modifier		 *list, *cmp = NULL, *search = NULL;
 	struct format_modifier		**sub = NULL, *mexp = NULL, *fm;
 	struct format_modifier		 *bool_op_n = NULL;
-	u_int				  i, count, nsub = 0, nrep;
+	u_int				  i, count, nsub = 0, nrep, check = 0;
 	struct format_expand_state	  next;
 	struct environ_entry		 *envent;
 
@@ -5377,7 +5405,7 @@ format_replace(struct format_expand_state *es, const char *key, size_t keylen,
 	/* Is this a literal string? */
 	if (modifiers & FORMAT_LITERAL) {
 		format_log(es, "literal string is '%s'", copy);
-		value = format_unescape(es, copy);
+		value = format_unescape(es, copy, strlen(copy));
 		goto done;
 	}
 
@@ -5453,7 +5481,7 @@ format_replace(struct format_expand_state *es, const char *key, size_t keylen,
 		else {
 			value = xstrdup("");
 			for (i = 0; i < nrep; i++) {
-				if (!format_check_time(es)) {
+				if (!format_check_time(es, &check)) {
 					free(right);
 					free(left);
 					free(value);
@@ -5733,7 +5761,7 @@ format_expand1(struct format_expand_state *es, const char *fmt)
 	int			 ch, brackets;
 	char			 expanded[8192];
 
-	if (fmt == NULL || *fmt == '\0' || !format_check_time(es))
+	if (fmt == NULL || *fmt == '\0' || !format_check_time(es, NULL))
 		return (xstrdup(""));
 
 	if (es->loop == FORMAT_LOOP_LIMIT) {
diff --git a/input.c b/input.c
index aa7b0c0c..cd664360 100644
--- a/input.c
+++ b/input.c
@@ -3055,7 +3055,7 @@ input_osc_10(struct input_ctx *ictx, const char *p)
 			return;
 		c = window_pane_get_fg_control_client(wp);
 		if (c == -1) {
-			tty_default_colours(&defaults, wp);
+			tty_default_colours(&defaults, wp, NULL);
 			if (COLOUR_DEFAULT(defaults.fg))
 				c = window_pane_get_fg(wp);
 			else
diff --git a/layout.c b/layout.c
index 4cf5f8b8..73d93a81 100644
--- a/layout.c
+++ b/layout.c
@@ -624,18 +624,18 @@ layout_resize_set_size(struct window *w, struct layout_cell *lc,
 static struct layout_cell *
 layout_cell_get_neighbour_direction(struct layout_cell *lc, int direction)
 {
-	struct layout_cell	*lcneighbour = lc;
+	struct layout_cell	*lcn = lc;
 
 	while (1) {
 		if (direction)
-			lcneighbour = TAILQ_NEXT(lcneighbour, entry);
+			lcn = TAILQ_NEXT(lcn, entry);
 		else
-			lcneighbour = TAILQ_PREV(lcneighbour, layout_cells,
-			    entry);
+			lcn = TAILQ_PREV(lcn, layout_cells, entry);
 
-		if (lcneighbour == NULL || layout_cell_is_tiled(lcneighbour) ||
-		    layout_cell_has_tiled_child(lcneighbour))
-			return (lcneighbour);
+		if (lcn == NULL ||
+		    layout_cell_is_tiled(lcn) ||
+		    layout_cell_has_tiled_child(lcn))
+			return (lcn);
 	}
 }
 
@@ -660,19 +660,17 @@ layout_cell_get_neighbour(struct layout_cell *lc)
 	if (lcother == NULL)
 		lcother = layout_cell_get_neighbour_direction(lc, !direction);
 
-	return lcother;
+	return (lcother);
 }
 
-/*
- * Destroy a cell and redistribute the space if the cell was tiled. Assumes
- * to be called on a leaf cell.
- */
+
+/* Destroy a cell and redistribute the space. */
 void
 layout_destroy_cell(struct window *w, struct layout_cell *lc,
     struct layout_cell **lcroot)
 {
-	struct layout_cell     *lcother, *lcparent;
-	int			val;
+	struct layout_cell	*lcother = NULL, *lcparent;
+	int			 change;
 
 	/*
 	 * If no parent, this is either a floating pane or the last
@@ -696,10 +694,10 @@ layout_destroy_cell(struct window *w, struct layout_cell *lc,
 	lcother = layout_cell_get_neighbour(lc);
 	if (lcother != NULL) {
 		if (lcparent->type == LAYOUT_LEFTRIGHT)
-			val = lc->sx + 1;
+			change = lc->sx + 1;
 		else
-			val = lc->sy + 1;
-		layout_resize_adjust(w, lcother, lcparent->type, val);
+			change = lc->sy + 1;
+		layout_resize_adjust(w, lcother, lcparent->type, change);
 	} else
 		layout_remove_tile(w, lcparent);
 
@@ -1694,7 +1692,7 @@ layout_get_floating_cell(struct cmdq_item *item, struct args *args,
 }
 
 /*
- * Removes a cell from the tiled layout by giving half the cells space to the
+ * Removes a cell from the tiled layout by giving the cell's space to the
  * nearest neighbour.
  */
 int
diff --git a/popup.c b/popup.c
index 999e4066..733aa3d7 100644
--- a/popup.c
+++ b/popup.c
@@ -327,6 +327,7 @@ popup_draw_cb(struct client *c, void *data, struct screen_redraw_ctx *rctx)
 		defaults.bg = pd->palette.bg;
 	style_ctx.defaults = &defaults;
 	style_ctx.palette = &pd->palette;
+	style_ctx.dim = 0;
 	style_ctx.hyperlinks = s.hyperlinks;
 
 	if (pd->md != NULL) {
diff --git a/regress/format-strings.sh b/regress/format-strings.sh
index 8d192ed2..bae66ab0 100644
--- a/regress/format-strings.sh
+++ b/regress/format-strings.sh
@@ -67,6 +67,7 @@ $TMUX set @true 1 || exit 1
 $TMUX set @false 0 || exit 1
 $TMUX set @warm Summer || exit 1
 $TMUX set @cold Winter || exit 1
+$TMUX set @v 'foo:bar' || exit 1
 
 # Plain string without substitutions et al
 test_format "abc xyz" "abc xyz"
@@ -74,6 +75,8 @@ test_format "abc xyz" "abc xyz"
 # Test basic escapes for "#", "{", "#{" "}", "#}", ","
 test_format "##" "#"
 test_format "#," ","
+test_format "#{s/#:/_/:@v}" "foo_bar"
+test_format "#{s/o/#:/:@v}" "f:::bar"
 test_format "{" "{"
 test_format "##{" "#{"
 test_format "#}" "}"
diff --git a/screen-redraw.c b/screen-redraw.c
index e1a5655b..092ebcaa 100644
--- a/screen-redraw.c
+++ b/screen-redraw.c
@@ -1214,7 +1214,7 @@ screen_redraw_draw_pane(struct screen_redraw_ctx *ctx, struct window_pane *wp)
 		}
 
 		/* Set up the default style. */
-		tty_default_colours(&defaults, wp);
+		tty_default_colours(&defaults, wp, &style_ctx.dim);
 		style_ctx.defaults = &defaults;
 		style_ctx.palette = palette;
 		style_ctx.hyperlinks = s->hyperlinks;
diff --git a/screen-write.c b/screen-write.c
index d1104042..dd46e9a1 100644
--- a/screen-write.c
+++ b/screen-write.c
@@ -255,7 +255,8 @@ screen_write_initctx(struct screen_write_ctx *ctx, struct tty_ctx *ttyctx,
 	} else {
 		ttyctx->redraw_cb = screen_write_redraw_cb;
 		if (ctx->wp != NULL) {
-			tty_default_colours(&ttyctx->defaults, ctx->wp);
+			tty_default_colours(&ttyctx->defaults, ctx->wp,
+			    &ttyctx->style_ctx.dim);
 			ttyctx->style_ctx.palette = &ctx->wp->palette;
 			ttyctx->set_client_cb = screen_write_set_client_cb;
 			ttyctx->arg = ctx->wp;
diff --git a/server-client.c b/server-client.c
index 8f696e50..d001fe5d 100644
--- a/server-client.c
+++ b/server-client.c
@@ -2014,16 +2014,32 @@ server_client_check_modes(struct client *c)
 	}
 }
 
+/* Check if any panes need to be redrawn. */
+static int
+server_client_any_pane_redraw(struct client *c)
+{
+	struct session		*s = c->session;
+	struct window		*w = s->curw->window;
+	struct window_pane	*wp;
+
+	if (c->flags & CLIENT_REDRAWWINDOW)
+		return (1);
+	TAILQ_FOREACH(wp, &w->panes, entry) {
+		if (wp->flags & (PANE_REDRAW|PANE_REDRAWSCROLLBAR))
+			return (1);
+	}
+	return (0);
+}
+
 /* Check for client redraws. */
 static void
 server_client_check_redraw(struct client *c)
 {
 	struct session		*s = c->session;
 	struct tty		*tty = &c->tty;
-	struct window		*w = c->session->curw->window;
+	struct window		*w = s->curw->window;
 	struct window_pane	*wp;
 	int			 needed, tflags, mode = tty->mode;
-	uint64_t		 client_flags = 0;
 	struct timeval		 tv = { .tv_usec = 1000 };
 	static struct event	 ev;
 	size_t			 n;
@@ -2042,20 +2058,8 @@ server_client_check_redraw(struct client *c)
 	needed = 0;
 	if (c->flags & CLIENT_ALLREDRAWFLAGS)
 		needed = 1;
-	else {
-		TAILQ_FOREACH(wp, &w->panes, entry) {
-			if (wp->flags & PANE_REDRAW) {
-				needed = 1;
-				client_flags |= CLIENT_REDRAWWINDOW;
-				break;
-			}
-			if (wp->flags & PANE_REDRAWSCROLLBAR) {
-				needed = 1;
-				client_flags |= CLIENT_REDRAWWINDOW;
-				/* no break - later panes may need redraw */
-			}
-		}
-	}
+	else if (server_client_any_pane_redraw(c))
+		needed = 1;
 	if (!needed) {
 		c->flags &= ~CLIENT_STATUSFORCE;
 		return;
@@ -2078,7 +2082,8 @@ server_client_check_redraw(struct client *c)
 			log_debug("redraw timer started");
 			evtimer_add(&ev, &tv);
 		}
-		c->flags |= client_flags;
+		if (server_client_any_pane_redraw(c))
+			c->flags |= CLIENT_REDRAWWINDOW;
 		return;
 	}
 
diff --git a/style.c b/style.c
index 586e9f93..b79d3291 100644
--- a/style.c
+++ b/style.c
@@ -32,6 +32,7 @@
 static struct style style_default = {
 	{ { { ' ' }, 0, 1, 1 }, 0, 0, 8, 8, 0, 0 },
 	0,
+	0,
 
 	8,
 	STYLE_ALIGN_DEFAULT,
@@ -201,6 +202,13 @@ style_parse(struct style *sy, const struct grid_cell *base, const char *in)
 			if ((value = colour_fromstring(tmp + 5)) == -1)
 				goto error;
 			sy->fill = value;
+		} else if (end > 4 && strncasecmp(tmp, "dim=", 4) == 0) {
+			if (tmp[end - 1] == '%')
+				tmp[end - 1] = '\0';
+			n = strtonum(tmp + 4, 0, 100, &errstr);
+			if (errstr != NULL)
+				goto error;
+			sy->dim = n;
 		} else if (end > 3 && strncasecmp(tmp + 1, "g=", 2) == 0) {
 			if ((value = colour_fromstring(tmp + 3)) == -1)
 				goto error;
@@ -346,6 +354,11 @@ style_tostring(struct style *sy)
 		    colour_tostring(sy->fill));
 		comma = ",";
 	}
+	if (sy->dim != 0) {
+		off += xsnprintf(s + off, sizeof s - off, "%sdim=%d%%", comma,
+		    sy->dim);
+		comma = ",";
+	}
 	if (gc->fg != 8) {
 		off += xsnprintf(s + off, sizeof s - off, "%sfg=%s", comma,
 		    colour_tostring(gc->fg));
@@ -386,7 +399,7 @@ style_tostring(struct style *sy)
 }
 
 /* Apply a style on top of the given style. */
-void
+struct style *
 style_add(struct grid_cell *gc, struct options *oo, const char *name,
     struct format_tree *ft)
 {
@@ -409,6 +422,7 @@ style_add(struct grid_cell *gc, struct options *oo, const char *name,
 
 	if (ft0 != NULL)
 		format_free(ft0);
+	return (sy);
 }
 
 /* Apply a style on top of the default style. */
diff --git a/tmux.1 b/tmux.1
index f3240b4d..9a7e1a60 100644
--- a/tmux.1
+++ b/tmux.1
@@ -7140,6 +7140,9 @@ is the terminal alternate character set.
 Align text to the left, centre or right of the available space if appropriate.
 .It Ic fill=colour
 Fill the available space with a background colour if appropriate.
+.It Ic dim=percentage
+Dim foreground and background colours by
+.Ar percentage .
 .It Ic width=N
 Set the width of the styled area.
 .Ar N
diff --git a/tmux.h b/tmux.h
index c64c936b..893e9b28 100644
--- a/tmux.h
+++ b/tmux.h
@@ -955,6 +955,7 @@ enum style_default_type {
 struct style {
 	struct grid_cell	gc;
 	int			ignore;
+	int			dim;
 
 	int			fill;
 	enum style_align	align;
@@ -1330,6 +1331,8 @@ struct window_pane {
 
 	struct grid_cell cached_gc;
 	struct grid_cell cached_active_gc;
+	u_int		 cached_dim;
+	u_int		 cached_active_dim;
 	struct colour_palette palette;
 	enum client_theme last_theme;
 	struct style_line_entry border_status_line;
@@ -1671,6 +1674,7 @@ LIST_HEAD(tty_terms, tty_term);
 struct tty_style_ctx {
 	const struct grid_cell	*defaults;
 	struct colour_palette	*palette;
+	u_int			 dim;
 	struct hyperlinks	*hyperlinks;
 };
 
@@ -2773,7 +2777,7 @@ void	tty_cmd_sixelimage(struct tty *, const struct tty_ctx *);
 void	tty_draw_images(struct client *, struct window_pane *, struct screen *);
 #endif
 void	tty_cmd_syncstart(struct tty *, const struct tty_ctx *);
-void	tty_default_colours(struct grid_cell *, struct window_pane *);
+void	tty_default_colours(struct grid_cell *, struct window_pane *, u_int *);
 
 /* tty-term.c */
 extern struct tty_terms tty_terms;
@@ -3210,6 +3214,7 @@ int	 colour_find_rgb(u_char, u_char, u_char);
 int	 colour_join_rgb(u_char, u_char, u_char);
 void	 colour_split_rgb(int, u_char *, u_char *, u_char *);
 int	 colour_force_rgb(int);
+int	 colour_dim(int, u_int);
 const char *colour_tostring(int);
 enum client_theme colour_totheme(int);
 int	 colour_fromstring(const char *);
@@ -3878,7 +3883,7 @@ int		 popup_modify(struct client *, const char *, const char *,
 int		 style_parse(struct style *,const struct grid_cell *,
 		     const char *);
 const char	*style_tostring(struct style *);
-void		 style_add(struct grid_cell *, struct options *,
+struct style	*style_add(struct grid_cell *, struct options *,
 		     const char *, struct format_tree *);
 void		 style_apply(struct grid_cell *, struct options *,
 		     const char *, struct format_tree *);
diff --git a/tty.c b/tty.c
index b1c2e84c..bd1b289c 100644
--- a/tty.c
+++ b/tty.c
@@ -85,7 +85,7 @@ static void	tty_write_one(void (*)(struct tty *, const struct tty_ctx *),
 #define TTY_REQUEST_LIMIT 30
 
 static struct tty_style_ctx tty_default_style_ctx = {
-	&grid_default_cell, NULL, NULL
+	&grid_default_cell, NULL, 0, NULL
 };
 
 void
@@ -2730,16 +2730,39 @@ tty_hyperlink(struct tty *tty, const struct grid_cell *gc,
 		tty_putcode_ss(tty, TTYC_HLS, id, uri);
 }
 
+static int
+tty_dim_default_colour(struct tty *tty, int c, int foreground)
+{
+	enum client_theme	 theme;
+
+	if (!COLOUR_DEFAULT(c))
+		return (c);
+
+	if (foreground && tty->fg != -1)
+		return (tty->fg);
+	if (!foreground && tty->bg != -1)
+		return (tty->bg);
+
+	theme = tty->client->theme;
+	if (theme == THEME_DARK)
+		return (foreground ? 7 : 0);
+	if (theme == THEME_LIGHT)
+		return (foreground ? 0 : 7);
+	return (c);
+}
+
 void
 tty_attributes(struct tty *tty, const struct grid_cell *gc,
     const struct tty_style_ctx *style_ctx)
 {
 	struct grid_cell	*tc = &tty->cell, gc2;
+	struct colour_palette	*palette;
 	int			 changed;
 
 	/* Use default style if not given. */
 	if (style_ctx == NULL)
 		style_ctx = &tty_default_style_ctx;
+	palette = style_ctx->palette;
 
 	/* Copy cell and update default colours. */
 	memcpy(&gc2, gc, sizeof gc2);
@@ -2748,6 +2771,24 @@ tty_attributes(struct tty *tty, const struct grid_cell *gc,
 			gc2.fg = style_ctx->defaults->fg;
 		if (gc2.bg == 8)
 			gc2.bg = style_ctx->defaults->bg;
+		if (palette != NULL) {
+			changed = colour_palette_get(palette, gc2.fg);
+			if (changed != -1)
+				gc2.fg = changed;
+			changed = colour_palette_get(palette, gc2.bg);
+			if (changed != -1)
+				gc2.bg = changed;
+		}
+	}
+	if (style_ctx->dim != 0) {
+		gc2.fg = tty_dim_default_colour(tty, gc2.fg, 1);
+		gc2.bg = tty_dim_default_colour(tty, gc2.bg, 0);
+		changed = colour_dim(gc2.fg, style_ctx->dim);
+		if (changed != -1)
+			gc2.fg = changed;
+		changed = colour_dim(gc2.bg, style_ctx->dim);
+		if (changed != -1)
+			gc2.bg = changed;
 	}
 
 	/* Ignore cell if it is the same as the last one. */
@@ -2774,9 +2815,9 @@ tty_attributes(struct tty *tty, const struct grid_cell *gc,
 	}
 
 	/* Fix up the colours if necessary. */
-	tty_check_fg(tty, style_ctx->palette, &gc2);
-	tty_check_bg(tty, style_ctx->palette, &gc2);
-	tty_check_us(tty, style_ctx->palette, &gc2);
+	tty_check_fg(tty, palette, &gc2);
+	tty_check_bg(tty, palette, &gc2);
+	tty_check_us(tty, palette, &gc2);
 
 	/*
 	 * If any bits are being cleared or the underline colour is now default,
@@ -3209,7 +3250,7 @@ tty_style_changed(struct window_pane *wp)
 }
 
 void
-tty_default_colours(struct grid_cell *gc, struct window_pane *wp)
+tty_default_colours(struct grid_cell *gc, struct window_pane *wp, u_int *dim)
 {
 	if (wp->flags & PANE_STYLECHANGED)
 		tty_style_changed (wp);
@@ -3223,6 +3264,13 @@ tty_default_colours(struct grid_cell *gc, struct window_pane *wp)
 		gc->bg = wp->cached_active_gc.bg;
 	else
 		gc->bg = wp->cached_gc.bg;
+
+	if (dim != NULL) {
+		if (wp == wp->window->active)
+			*dim = wp->cached_active_dim;
+		else
+			*dim = wp->cached_dim;
+	}
 }
 
 void
diff --git a/window.c b/window.c
index 2534010f..797dfb20 100644
--- a/window.c
+++ b/window.c
@@ -611,6 +611,8 @@ window_redraw_active_switch(struct window *w, struct window_pane *wp)
 		gc2 = &wp->cached_active_gc;
 		if (!grid_cells_look_equal(gc1, gc2))
 			wp->flags |= PANE_REDRAW;
+		else if (wp->cached_dim != wp->cached_active_dim)
+			wp->flags |= PANE_REDRAW;
 		else {
 			c1 = window_pane_get_palette(wp, gc1->fg);
 			c2 = window_pane_get_palette(wp, gc2->fg);
@@ -2005,7 +2007,7 @@ window_pane_get_bg(struct window_pane *wp)
 
 	c = window_pane_get_bg_control_client(wp);
 	if (c == -1) {
-		tty_default_colours(&defaults, wp);
+		tty_default_colours(&defaults, wp, NULL);
 		if (COLOUR_DEFAULT(defaults.bg))
 			c = window_get_bg_client(wp);
 		else
diff --git a/xmalloc.c b/xmalloc.c
index d11d8dc7..14e805ed 100644
--- a/xmalloc.c
+++ b/xmalloc.c
@@ -105,6 +105,18 @@ xstrndup(const char *str, size_t maxlen)
 	return cp;
 }
 
+char *
+xmemdup(const void *ptr, size_t len)
+{
+	char *cp;
+
+	cp = xmalloc(len + 1);
+	if (len != 0)
+		memcpy(cp, ptr, len);
+	cp[len] = '\0';
+	return cp;
+}
+
 int
 xasprintf(char **ret, const char *fmt, ...)
 {
diff --git a/xmalloc.h b/xmalloc.h
index 26009dd8..a87f053b 100644
--- a/xmalloc.h
+++ b/xmalloc.h
@@ -30,6 +30,7 @@ void	*xreallocarray(void *, size_t, size_t);
 void	*xrecallocarray(void *, size_t, size_t, size_t);
 char	*xstrdup(const char *);
 char	*xstrndup(const char *, size_t);
+char	*xmemdup(const void *, size_t);
 int	 xasprintf(char **, const char *, ...)
 		__attribute__((__format__ (printf, 2, 3)))
 		__attribute__((__nonnull__ (2)));