Most chips will transfer their color to whatever is next to them. If you house them in a transparent holder, like a flip or plastic page, you will see the transferred color more easily. Better to bleed to the page than a chip next to them if you just keep them stacked in a box.

Note that it's not the PVC (polyvinyl chloride) that facilitates the dye transfer, but the plasticizer added to the holder to makes it more pliable.

I've been keeping most of my chips in 30 pocket plastic pages for at least a dozen years and have no plans to change. I use the Dansco binders for baccarat and oversize chips because of the multiple sizes.

Someone asked if there is a consensus on the use or not use of pvc holder for chips; I don't think there is. A case can be made for not storing coins in pvc, but chips are mostly plastic anyway. I don't worry about it.