Leonardo da Vinci, in 1490, was the first to use, and expand upon the concepts of the color wheel, and the theory of color. The use of primary colors enhanced the importance of colour theory, and is one of the reasons we still use it today.
http://www.colors-4life.com/color-theory.html
ACTIVITY: Determining Your Eye Color
http://www.color-chart.org/eye-color-chart.php
Worksheet: http://illuminations.nctm.org/Lessons/EyeToEye/Eye-AS-EyeColor.pdf
Video: Color Mixing Wheel
http://youtu.be/WYZWDEmLR90