Show Symbols remain white

[ppage]

I have a theme with a very light background set for the dialog box and a good strong colored purple for the text. All works well apart from when you select "Show Symbols" from the menu when composing an email and all symbols and controls are still an off white, too light to be seen against my light background.
So my question is how do I change the color of the symbols in the Show Symbols dialog screen? I have seen it done on other themes but just can't see how. Seems to be the same for version 5 and 6.