The anime albums I stole the white trays from were pretty white, not sure they will match the KICA style of the 90s, although if damaged and/or faded enough, I wouldn't hesitate to replace it anyway.
If you were in Japan I'm sure you could buy shopping carts full of cheap crappy albums in good condition with white trays that have a nice "Compact Disc Digital Audio" double logo and no one would notice the swap
But are you sure they are of a different white? The few KICA-10XX I have right here seem to be pretty white, as in white
Oh and yeah, that's why black trays are better... they can't really sunfade... although there are zillion different models.