How to get the colors??

Greetings Every1,
I'm developing a custom Command Button. It resembles the Win32 style command button. I'm giving it a property Backcolor, which can be changed to any color. The problem, is when i specify this color, i must somehow find out the Hightlight & the shadow color which window uses to give a 3D effect to the button. To the standard win32 button, these r a variation of gray colors, but suppose if i use red as my color, how must i calculate my highlight & shadow colors. This is a difficult problem i suppose, but i'll be glad if some1 will plz help me. Thanq.

If you add an option button, and set its style to graphical, you basically get a command button.
And if you change the backcolour of that, the shadowcolours stay the same - ie. grey.