Enzotech BMR-C1-LE Memory Ramsink (Black)

I wrote Enzotech support asking if the black finish acts as a heat insulator. They got back quickly writing, "The matte black color does not make the BMR-C1-LE less heat conductive compared to the pure copper finish of the BMR-C1 they work the same."

It's not paint I'm not sure what the process is for that matte black finish I'm checking with my team but it does not act as an insulator.