Author: Lou Adler

Can your video handle 16, 256, 32768, 16777216, or more colors?

Answer:

You can use WIN API function GetDeviceCaps() to calculate the number of colors 
supported by the current video mode. To make it even easier to use, here's a 
function that will simply return the number of maximum simultaneous colors current 
video device can handle:

1   function GetColorsCount: integer;
2   var
3     h: hDC;
4   begin
5     Result := 0;
6     try
7       h := GetDC(0);
8       Result :=
9         1 shl
10        (
11        GetDeviceCaps(h, PLANES) *
12        GetDeviceCaps(h, BITSPIXEL)
13        );
14    finally
15      ReleaseDC(0, h);
16    end;
17  end;