Color is inherited down the maternal line and both non-reproduction time and reproduction time mutations should tweak the color over time as with asexual reproduction.
Note that virus infections and (I think maybe) sexual reproduction may bump the mutation count, giving a false indication of the number of actual mutations. The logic here is that I write to the mutation details and bump the counter anytime the genome is changed. I should probably do the same when .delgene does something for consistency, or perhaps invent a new catagory for this non-mutation genome changing occurances. But at the momnent, color isn't changed when these things happen - only when actual mutations occur.
And of course, I could always have a bug. Open one if you think so.