If they are anything like the Whyte carbon, it's a coating. It's not great, but if you shoot with a glove normally, it's not horrible either. It's basically the same thing as the "wood grain" CF shafts on Aliexpress.
There's a company called Proqure that has different colored "carbon", but I couldn't get a straight answer out of them if it's a coating or not, so I'd say it most likely is. I'd be happy to be wrong though.
I'd love for a company to come up with a method or formulation to tint or color carbon fiber. I'd be interested to see if something like a graphene sheet could be colored and roll or filament wind a shell over a quality CF shaft.