Sets the color of a particular pixel. You should ensure that
the color provided is in the same color space as the BitmapData. If
it is not then the color channels requested will be absent and so
components will not be changed. Also consider that your source
pixels may have transparency so you may wish to call LockBits with
a PixelFormat that supports Alpha.
void SetPixel(int x, int y, Color color);
Sub SetPixel(x As Integer, y As Integer, color As Color)