I have 4 amstrad plusses, 2 464's and 2 6128's. One of each is yellowed, an the other white. The yellow 6128 is one I bought new, and has been smoke free its entire life.Your opinion of course, i already have three 464plus machines none of them yellowing, so i don't see the 6128 plus being any different. they yellow mainly because of smoke damage not age and I'm sure i will acquire one in good, clean condition, i just have to wait that's all.