Color touming;
Bitmap bit = new Bitmap(imageList1.Images[200]);
for (int y = 1; y < imageList1.Images[200].Height; y++)
{
for (int x = 1; x < imageList1.Images[200].Width; x++)
{
touming = bit.GetPixel(x, y);
if (touming != Color.White)
{
bit.MakeTransparent(bit.GetPixel(x, y));