Dahlias: Do dahlias revert?, 1 by Poochella

Poochella wrote:
Should have known: the article was by Wayne Holland of "HY" dahlia origination fame, now moved on to growing wine grapes, I've read. Hy Lobster is one of my all time favorite red dahlias.

Good luck with this article. I had the usually entirely red Riverdance show up pure yellow one year on one branch only, but was unable to save remnants of that branch for propagation. It was fun while it lasted though. Haven't had such color weirdness since on any plant, but perhaps something similar happened to turn your friend's dahlias pink.
http://davesgarden.com/community/forums/t/649055/

http://www.members.shaw.ca/hydahlia/mutation.html