Well I decided to order a 4 cluster blue LED because I was very disappointed with the light bulb that my trackball came with.
It is pretty obvious that there is a huge difference between the two in the pics. It is even more noticeable in person and you can actually see the trackball glow when the lights are on. It isn't too bright for me and I think it looks great now.
Bottom Line: Highly recommended for the price.
The cost was $7.59 for the LED (w/ shipping) from
www.superbrightleds.comI used the blue WLED 4-LED bulb (12VDC 4-LED Wedge Base Bulb 194/168 type) and made a small bracket to get the LED pointing straight into the trackball.
Here are some pics...