The only information found regarding two different color eyes; is a slight mutation where the genes for eye color share an allele; and one eye gets them (paired allele) and the other doesn't.
With female boxies having red eyes one boxie breeder believes that certain boxies are an alpha type (more aggressive towards other boxies) and will try to dominate other boxies in their territorial area. ( NO PROOF OF THIS )
This is not something I know of, but just heard. My female is a very gentle one towards humans...But I might introduce her to other females and observe. She willing lets my males breed her.
Strange the breeding behavior you described regarding your three toed. I don't think it is anything to do with eye color....
Possibly hormones. Was she keep warm, active during the winter or did she hibernate in the outdoors?
Although it's rare, people occasionally have two different color eyes. Same reason (shared alleles).
I'm just hoping that all the offspring that I get from this Red Eyed female are Red Eyed regardless of their sex .
Thanks,
Ric