Help needed with menu setting

I am using the Vista skin and noticed that the border around an activated menu is white. Can this be changed - I looked for the appropriate colour box but could not find it.

The second thing I noticed is that the black gradient on the button mouseover does not scale up smoothly when larger button sizes are used (horizontal lines appear). Is it possible to to replace this - if so what width and height should be used - I can create it in Flash and export it.

Cheers
Brian