What do you mean by the frame colour? Are you aware that you can change the global colour scheme in windows settings, and VC6 should then respect these changes?
How you change the windows colour settings depends on your OS. For winXP use:
Control Panel -> Display -> Appearance tab -> Advanced button
here you can set the colours for various window components.
Unfortunately no, this is not something that VA will do, and it is not something we are looking to try and add. You could look into something like WindowBlinds by Stardock, since this can be used to control the look of an individual program. Please be aware to that WindowBlinds has been known to cause problems with VA displaying tooltips correctly. Still, it might help you do what you want here: