Conversation so far:
which receptor in the eye is responsible for perceiving color
Cone cells, or cones, are photoreceptor cells in the retinas of vertebrate eyes. They are responsible for color vision.
how many cone cells are there in the human eye
There are about six to seven million cone cells in a human eye and are most concentrated towards the macula.

Question: what types are there
Self-contained rewrite: what types of cone cells are there