[Question] How to change dialogbox background image and fonts colors?

I am already finished my cosmetic GUI mod for BG2EE v2+, but I cannot change the last thing - the dialogbox image background and font colors of that box. In the previous version, I changed GUWBTP.MOS or something like that, - and its worked fine. But now I have checked UI.menu fields near 11730, and found no references on any MOS .
So how I can change that stuff?

Thanx for the answers.