It is generally known that even in the dark ages - i.e. the viking period - the merchant class and the nobility had access to dyed clothing and wore them routinely. Heck, if you were wealthy enough you could even get silk but that was truly special. Some dyes were cheap, others expensive. The expensive stuff was used on their finest gear. the cheap stuff was for everyday. The poor, well, there were sumptuary laws that said they weren’t allowed to wear fancy clothes (because ... poor) but those were hardly ever enforced. But we’re talking about the poor so yeah, dyes might have been an issue. But that doesn’t mean they never used them and lived in a pallet of brown and off-white.