Ed...I have found out the hard way over the last 3-4 years that I've been cooking engines in the crockpot 'o antifreeze what comes off and what doesn't...

Most anodized parts come back out just fine, but I have had a few that the color got a little bit lighter.
When I first started doing it I used too much heat...and I think that might have had something to do with bleaching out the color...(I have a pink head from an old McCoy now...)

The black from my .80GK was chipped and flaking off from the cyl. when I got it used from an old friend. I decided to just throw the jug in w/ some other engines/parts while I worked on removing the crank / bearings from the lower case...
When I pulled the jug out of the bath, most of the black was gone, and the rest came off w/ a tooth brush.