What could an underwater civilization use to produce makeup and cosmetics? Considering that:
The merfolk's tech level is the same as ours (they have fire and metallurgy thanks to magic)
Makeup effects should be similar to those more conventionally used by humans (eyeshadow, blush, eyeliner, lipstick, concealer, etc.)
They do not trade with the surface so the raw materials have to come exclusively from the sea or coastal regions
Makeup needs to be done in a more compact way, so that it doesn't spread in the water
Makeup needs to be waterproof (duh)
I apologize for any mistakes, English is not my mother language.