GNOME Bugzilla – Bug 680885
GtkColorButton color swatch suboptimal when color ~= background color
Last modified: 2014-07-10 00:53:30 UTC
If the selected color in the color button is close to the background color specified by the theme for the button, they visually merge together, making it difficult to recognize the actual color.
being able to use a shadow or borders on the color bit would fix it