Color Module: Impossible to use a defined color twice in filling for background images

With base.png you can define as many fancy graphics as you like as black and white transparent png-24. By underlying it with colors you define you can theoratically slice out as many background graphics as you want in diverse colors.

You define which areas below the png to fill in what color in the "fill" array:

 // Color areas to fill (x, y, width, height).
  'fill' => array(
    'gradient-block' => array(0, 0, 10, 250),
    'header-bar' => array(0, 250, 10, 146),
    'base' => array(0, 1590, 1000, 10),
    'header-bar' => array(11, 250, 29, 146),
  ),
// defined colors from a color scheme
 'base' => '#555555',
 'gradient-block' => '#444444',
 'header-bar' => '#444444',

 

Now what I have written here does not work at the moment: if you use one defined color (header-bar, in this case) for two different areas of recoloring, it does not color either of them, or only one, or maybe colors them completely in black. One can only use each defined color once in the fill array.

There are sure workarounds: the worst being defining a gazillion of colors, which makes it impossible for a user to change the colors in the backend due to sheer number.
The other one is to place graphics that shall get the same background color in adjacend regions and thus color a bigger area from which you cut out the images.

Neither is really satisfactory and also not necessary, since this is sure a bug. One should be able to define a color once and use it as many times as one wants to recolor base.png.