I'd recommend the kit from z327. It's available on eBay, search for z327. It's made well, inexpensive, and he'll answer all of your questions. He doesn't believe that his silver kits have changed color, but I went with the blue (silver car).

 

All the ground kits that are made with high end stereo power cable will change over time. The OFC wire is covered by clear or colored PVC. While PVC is tolerant of chemicals and moderate heat (rated to 60 degrees C) it does change when subjected to repeated heat cycles. Its just a question of time. Some cable makers use thicker PVC and that seems to delay the process. The effectiveness of the kit should not change only the appearance. IMHO

Mylar is much better at withstanding temperature cycling then PVC (rated to 125 degrees C) so I would expect the Max Ground kit from Courtesy to hold up much better.