Prehistoric cave paintings

What was used for the paint?

according to the wiki article on Lascaux:

Just about whatever was available: charcoal, ground bones, berries, oxidized minerals, blood, etc.

A more interesting question would be how were the caves lit, without using up the oxygen and covering everything with smoke?

Oops, I skimmed over the article before posting but didn’t see that.

panache45, that is a pretty good question.

The room with most of the paintings is not especially deep in the cave and is quite large (apparently around 66’ wide and 16’ high) - so it would take a serious fire to use up the oxygen.