Dynamic button color for powerpoint ribbon control

I am looking for a way to dynamically change the color of a button control in the power point ribbon for an add-in I am developing using VBA.

I want a user to be able to define a color using RGB values and for a button control of that color to render in the ribbon (i.e. an icon of 32 x 32 pixels that is that color). I will then use these controls to work in a similar way to a color palette for changing shape fill, outline color and text color.

Because of the huge number different color combinations (256^3) it will not be possible to save icon files for every possible RGB color to use in the ribbon.

Any advice or a solution will be highly appreciated.

Thanks