How to limit/select/edit the numbers of colors in BB Code ?

[DigitALL]

Hello,

I have searched this forum but could not find something related to the issue I have...

I have dark and light skins installed and when posting, if it is used the default text color, the post appears fine under each skin.
Here is my problem: for example, a member posts a text with grey color text to have a better contrast under the dark skin he prefers. But under a light skin where the background is light grey, the same text could be hardly seen.
Take for instance in this forum where the color palete/array is edited so if you want to write in "light grey" it will appear green.

I have currently disabled the "Allow Color BB Code" from ACP/Options/BB Code Settings so the members could post only in a default color. This looks fine but many members told me that they want the colors back, or at least few of them. I found that there are few colors that could be used under all skins.

How can I edit the color palette/array for text and use only the colors I want? I have searched in templates but it is not there... The palette/array has currently 40 colors. Is there a hack or info on how to control these colors, or better yet, make it to appear only 10 or 12 colors, please?