I've never had any fabric with 'modern' dyes show any fading at all and those processed with the older types of dyes will fade eventually no matter what you do.
My stash is very low-maintenance and I like it that way. I have more than enough to do to single-handedly maintain my house, property, vehicle, appliances, health, animals, budget, relationships, etc without spending time refolding fabric to avoid a possible fade line on the single 9" folded edge of the fabrics in my stash.
For me, the cost-benefit ratio of refolding idle fabric just doesn't support the effort involved.
