anyone seen this before?

[sunkool]

I have a green / red encrusting algae looking stuff growing on a rock. It's hard like coraline algae.

 

[Reefmack]

Sounds like a coralline but I've never seen that multi-color combination before - freaky looking but kinda pretty.

 

[Twisted]

most coralline algea I have encountered actually began with a greenish coloration of the area, then turned purple, so it sounds like the start of coralline to me.