It's the slightly sticky vinyl
It has that sort of yellowish cast to it. I figure I'm going to leave it alone (it would be a MAJOR project to do much of anything with it). I would like to build a wood cover to hide the yellow plastic refridgerator vent that comes up behind the kitchen counter. At least then I wouldn't have to look at that, and it probably wouldn't seem so 'yellow' in there with that hidden.
I'm heading over to HD today for some other stuff, I'll have to look for the microwave. Hers certainly fits in, looks very Airstream...