I got my first bjd in 2008 from Volks.The original color of the resin was called beauty white. There has been some yellowing,but it's not a bright yellow like I was worried about when I first heard of it. It's a darkish yellow and it's not splotchy,so it just looks like a darker resin doll,or even an antique doll. When I ruined the head and bought a replacement from another company,I got it in yellow so it would match the yellowed body and it worked. I didn't know the resin might get brittle over the years,but so far that hasn't happened to mine. I haven't noticed a difference between the old resin and new,but I just thought about it and maybe the new resin doesn't yellow as bad as the old. It makes sense because my doll from 2008 is the only one I have that's yellowed. I don't do anything extra to take care of the doll,it's already yellowed and modified. I know there are things you can do to prevent some yellowing,like keeping it out of the sun and don't use untrusted sealants and paints.