According to tests, GetDeviceCaps(NUMCOLORS) returns -1 for display DCs when the current display
mode is 8-bit on newer versions of Windows, which makes sense because lower bit depth display modes
are actually emulated with 32-bit modes.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=52679Signed-off-by: Zhiyi Zhang <zzhang@codeweavers.com>
Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>