This is an example of why using just the ghost effect wouldn't mix the colors. As you can see, the colors become darker and muddy, the original project is simulating what it would look like if the rgb values are added together (for example, r = (255,0,0) and b = (0,0,255), these added together gets a magenta that equals (255,0,255)). The original project uses pen to accomplish this pretty incredible effect, and draws the colors every time it can, which is why it's so laggy. An optimization would be to draw only if one or more of the circles moves
