Friend of mine ran a Lane #1 Hybrid Dirty Bomb (a Brunswick PK17/PK18 hybrid, if I remember correctly) through his dishwasher this week in advance of me doing a resurface for him. Turned the ball almost light blue and gray (the ball is a navy blue/purple mix, ordinarily).
So he brings it to me, I do a cleaning and resurface on my spinner, taking it down to 360 Abralon (we're going to start there and move up to 500 if needed -- all his equipment is similarly-drilled polished solids so we're just trying to get him a different look without having to buy a new ball). Once I took it down that far (I started at 500 Abralon, then decided to go a step further), the color phasing disappeared.
I've never had a problem using my dishwasher, so maybe his gets the water too hot?
Jess