View full lesson: ed.ted.com/lessons/how-we-see-color-colm-kelleher There are three types of color receptors in your eye: red, green and blue. But how do we see the amazing kaleidoscope of other colors that make up our world? Colm Kelleher explains how humans can see everything from auburn to aquamarine. Talk by Colm Kelleher, animation by TED-Ed.