diff --git a/tty.c b/tty.c
index 459db0a4..75986ef0 100644
--- a/tty.c
+++ b/tty.c
@@ -1005,6 +1005,8 @@ tty_attributes(struct tty *tty, const struct grid_cell *gc)
 	    (gc->flags & GRID_FLAG_FG256) != (tc->flags & GRID_FLAG_FG256)) {
 		tty_attributes_fg(tty, gc);
 		tc->fg = fg;
+		tc->flags &= ~GRID_FLAG_FG256;
+		tc->flags |= gc->flags & GRID_FLAG_FG256;
 	}
 
 	/* Set background colour. */
@@ -1012,6 +1014,8 @@ tty_attributes(struct tty *tty, const struct grid_cell *gc)
 	    (gc->flags & GRID_FLAG_BG256) != (tc->flags & GRID_FLAG_BG256)) {
 		tty_attributes_bg(tty, gc);
 		tc->bg = bg;
+		tc->flags &= ~GRID_FLAG_BG256;
+		tc->flags |= gc->flags & GRID_FLAG_BG256;
 	}
 }