I have found that if I open the graphics with GLGraphics 640,480,0 it will actually correctly report that the color depth is 5-bit red, 5-bit green, 5-bit blue, and 0-bit alpha (interesting that it is actually 15-bit color even though my display mode says 16-bit). It also correctly reports that there is no stencil buffer, no alpha buffer, and the depth buffer is 16-bit. Also GraphicsHertz() returns 60 even though the hz rate of the screen mode in the list of modes says 0, which is interesting.