if Image1.Picture.Graphic is TBitmap then
begin
case Image1.Picture.Bitmap.PixelFormat of
{Find color depth}
pf1bit: pf := '. Monochrome';
pf4bit: pf := '. 16 Colors';
pf8bit: pf := '. 256 Colors';
pf15bit: pf := '. 32768 Colors';
pf16bit: pf := '. 65536 Colors';
pf24bit: pf := '. 16 Million Colors';
pf32bit: pf := '. Gazillions of Colors!';
else
pf := '. Custom color scheme';
end;
end;