A year ago we decided that colored coins is the name of a concept, rather than a specific protocol. So many different protocols can exist.

It isn't necessarily a bad thing. Different protocols have different traits, and it is up to "the market" to decide which is the optimal one.

I expect that eventually one protocol will dominate, but we also can end up with different protocols being used for different things. It isn't a problem to implement several protocols in one wallet applications.