Preview theme colors in the theme picker

bin/blob-menu-select

@@ -7,8 +7,9 @@
 # blob:examples=blob menu select Format jpg png|blob-menu-select Resolution 4k 1080p 720p -- --width 400
 
 # An option may lead with an icon, as "<glyph><TAB><label>", and may trail a
-# subtext shown under the label, as "<glyph><TAB><label><TAB><subtext>". The
-# menu shows the glyph but never returns it. A plain option returns the label
+# subtext shown under the label, as "<glyph><TAB><label><TAB><subtext>", and
+# then space-separated hex colors drawn as swatches, as a fourth field. The
+# menu shows the glyph and swatches but never returns them. A plain option returns the label
 # alone; an option with a subtext returns "<label><TAB><subtext>", so callers
 # with same-named rows get the subtext back as the stable key.