Is there a way to tweak the colours on panel elements

[mezzmer]

I just set up the desktop on a v3.8 install, and I was wondering if there is a way to tweak individual elements on the tak bar.  I selected a primarily red theme, and the sected workplace switcher and the window button for the program with focus is a "baby blue" which looks lousy against the red background.  Is there any way I can tweak these elements, or do I have to find an theme with the colors I want.

Any suggestions would be much appreciated.