In my experience I had a white iPad 2 and I did notice the home button kind of yellowed overtime. Nothing to panic about but if you looked closely, the home button did become yellowish unlike the bezel. The bezel was perfectly white. Of course the glass protects te bezel while the home button has no layer for protection.
I had it for about a year.
But does OP enjoy Cheetos as much as you do? Because that matters.