Sunlight is really bad, but a few years of steady light of most kind can wash out the color of most chips.

If a buyer, just be careful of displays for sale.

If a collector, be careful of keeping your better chips in the light if you display.

Sometimes mild soap used in cleaning pales the chip a bit, but natural oils from your skin bring the color right back. Just hold them in your hand and go for a 2 mile run in New Orleans in the summer. The chips will look great!

Mark