Yes I think it must be a retcon, I had the vision of Nym as pale before ADWD but I was admittedly too lazy to look up a reference quote XD Ah well, technically she can be olive skinned and pale as you say, even olive skinned people can fail to get much sun but you can still distinguish their skin from a Caucasian complexion.

So AFFC, at least, definitely supports the fancasting above, lookswise!