How to change colors of contacts tooltip?

[excomax]

I'm using the data from svn trunk to compile Adium every now and then by myself. Now I thought, it would be nice if the tooltip showing up when hovering over the contact list would be black with white text like a HUD-window. That would fit much better into my desktop. The only thing is, that I don't know which file sets the color for it. If one of the developers could help me with that I would be very thankful.

Happy New Year by the way...