How do I enlarge the default cursor?

I'd like to use the default 'crosshair' cursor, perfect for my game because it changes colour to remain visible against any backdrop, but I'd ideally like it to be two or three times as big. I guess I could use a custom cursor and try to write the colour-changing code myself but I was wondering if there was a quick way just to enlarge it?

I don't know how to enlarge the cursor. When using a custom cursor, however, I don't think you'd need to write any color changing code. Just put the "Difference" effect on it.

Perfect! Thanks very much.