Welcome to Seven Forums kljw. I see some mention of running the application as administrator (right click exe and choose Run as administrator, this was on XP though where using the default blue theme also corrected this).
You mention changing colors, did you mean through Personalization
> Windows color
? 7. To Change the "Advanced Window Color and Appearance" Settings Window Color and Appearance - Change
I would play with 3D Objects
, Application background
, Message box
, and Window
. Note original settings before changing, so you can set them back if no help.
If no help, you might try running it in compatibility mode. A Guy