public void MakeTransparent(Color transparentColor) { // Make all the frames transparent. for (int f = 0; f < dgImage.NumFrames; f++) { Frame frame = dgImage.GetFrame(f); int color = transparentColor.ToArgb(); if (!Image.IsAlphaPixelFormat(PixelFormat)) { // Remove the alpha component. color = color & 0x00FFFFFF; } frame.MakeTransparent(color); } }