Question: How do we see colours and why can't we see more?

Liad Baruchin answered on 20 Jun 2015:

In a part of our eyes called the retina, we have a specific kind of cells called cones that are activated by light in different frequencies. When they are activated we perceive that as colour. We have cones that respond to light in the frequency of red, green and blue. Other colours are a combination of these colours and instead of activating just some of these cells they cause an activation of a few of them together. The reason we cannot see more colours is simply because we don’t have cells that repond to other light frequencies.