LSD makes colorblind person see color for the first time (2003) (erowid.org)

That is quite interesting. Having experimented quite a bit with various psychedelics myself, I find DMT to give the most colorful visuals by far. Curious how DMT is for colorblind people vs LSD. Anyone know?

What is the exact type of colorblindness here? Are multiple color receptors broken/missing instead of just one?