Perhaps this is a feature request, but I think the dyed collars of dogs (tame wolves) should work like the dyes on sheep. If I breed two blue sheep, I get a blue sheep. If I breed two dogs dyed blue, the pup grows to have a red collar.
I assume dyed collars were introduced to distinguish dogs owned by different players, so this would further that cause.
It's to distinguish dogs at all, not per player. I don't feel like this would work out well, sorry.