Hibiscus: Two different colored hibiscus flowers on same plant?, 1 by Grantman31

Grantman31 wrote:
I posted a thread below showing off my new Jane Cowl hibiscus "tree": http://davesgarden.com/community/forums/t/1079235/

The other day, I noticed something odd. Two different colored blooms on the same "tree"! One red, and the other pink. I've attached a picture of them side-by-side. I don't see any evidence of double-grafting, and the flower sprung from a branch that had a pink growing on it prior to this one blooming. I will keep watching the tree, but I thought this was very odd. Has anyone seen this?