video: Add a dark-grey console colour

This is useful for highlighting something with a black background, as
is needed with cedit when using a white-on-black console. Add this as
a new colour.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/boot/scene.c b/boot/scene.c
index 270c9c6..0135287 100644
--- a/boot/scene.c
+++ b/boot/scene.c
@@ -339,7 +339,7 @@
 
 	/* draw a background for the object */
 	if (CONFIG_IS_ENABLED(SYS_WHITE_ON_BLACK)) {
-		fore = VID_BLACK;
+		fore = VID_DARK_GREY;
 		back = VID_WHITE;
 	} else {
 		fore = VID_LIGHT_GRAY;
diff --git a/drivers/video/video-uclass.c b/drivers/video/video-uclass.c
index 9823673..a5b3e89 100644
--- a/drivers/video/video-uclass.c
+++ b/drivers/video/video-uclass.c
@@ -294,6 +294,9 @@
 	{ 0xff, 0x00, 0xff },  /* bright magenta */
 	{ 0x00, 0xff, 0xff },  /* bright cyan */
 	{ 0xff, 0xff, 0xff },  /* white */
+
+	/* an extra one for menus */
+	{ 0x40, 0x40, 0x40 },  /* dark gray */
 };
 
 u32 video_index_to_colour(struct video_priv *priv, enum colour_idx idx)
diff --git a/include/video.h b/include/video.h
index 606c8a3..fd19723 100644
--- a/include/video.h
+++ b/include/video.h
@@ -181,6 +181,7 @@
 	VID_LIGHT_MAGENTA,
 	VID_LIGHT_CYAN,
 	VID_WHITE,
+	VID_DARK_GREY,
 
 	VID_COLOUR_COUNT
 };