How to use it:
The top half shows the 'normal' spectrum. The bottom half shows the corresponding spectrum seen by a color blind person. Move the cursor to modify the degree of blindness for each type of color blindness (0.0: no anomaly, 1.0: maximum anomaly). Color blind people generally suffer from only one type of blindness. However some people have anomaly in several types, with the most severe case being achromatopsia (monochromatic vision).

How it works:
The simulator calculates the response at each wavelength of the visible spectrum using the CIE standard observer \(\overline{x},\overline{y},\overline{z}\) functions, and convert the resulting color from XYZ color space to sRGB color space. To account for color blindness, the wavelength is shifted in case of protanomaly, deuteranomaly, tritanomaly, or the XYZ values are dampen in case of protanopia, deuteranopia, tritanopia. Banding in the displayed spectrum is due to result colors out of the sRGB gamut.

Learn more about color blindness:

• Wikipedia
• Colour Blind Awareness
• "How color blindness works" by Human Interests on Youtube