How to check color-depth before displaying a window

Can I check the color-depth of the display device before displaying a window? I've used GetDeviceCaps() in OnInitialUpdate() in conjunction with a message box. This approach works OK, except before exiting the app, the client window flashes on the screen. Is there a method to check the device caps and/or exit the app either before m_pMainWnd is created or without flashing the screen?

TIA

Tom G