I have a main window as well as a secondary window which is occasionally displayed. The secondary window is a sort of suped-up tooltip, with controls like listboxes that can get focus. The problem is that when a control on my secondary window gets the focus, the title bar dims on my main window. Since the secondary window is a small item, it looks wrong to have the main window title bar dim. How do I keep the title bar in my main window from dimming when my secondary window gets the focus? I'm using C#, but any solution is okay (I can just use the PInvoke layer).

don't know how you do it in C#, but in win32 terms, handling the WM_NCACTIVATE msg and returning FALSE when wParam is FALSE will keep a window's title bar drawn as active.