I keep mine in 2 X 2 cardboard holders, in 20 slot mylar pages, in 3-ring
binders. I put the chip on the outside of the holder, not between the 2 halves.
The edges of the chip show up better on the page. I have had about 3 red chips bleed onto the mylar page, out of about 24,000 chips in pages & binders. As far
as I can tell, there has been no damage to the chips by fading or losing color.

However, I have had a few Sterling $5 tokens become frosted by being in PVC
pages.