Daltonism n. : Inability to perceive or distinguish certain colors, esp. red; color blindness. It has various forms and degrees. So called from the chemist Dalton, who had this infirmity.

Example:
Is it possible to hide a text in to a picture so that only people with Daltonism see it clearly?

Taxonomy
color blindness, cone, color blind, colors, color vision, wavelengths, X chromosome, anomalous trichromacy, mutation, pigments, hues, red-green, protanomaly, gene, spectrum, Tritanopia, eye, deuteranopia.

Defination from the web:
... color blindness; because of Dalton's work, the condition is often called daltonism, although this term is now used for a type of color ... This is one of the rarer forms of colorblindness making up about 1% of the male population, also known as Daltonism after John Dalton. ...