Sources Cited

Ishihara Test for Color Blindness
http://www.toledo-bend.com/colorblind/Ishihara.html

Colorblindness Problem Set 
http://www.biology.arizona.edu/human_bio/problem_sets/color_blindness/color_blindness.html

What is colorblindness?
http://kidshealth.org/kid/talk/qa/color_blind.html

Colorblindness Explained
http://members.shaw.ca/hidden-talents/vision/color/colorblind1.html