Which Colors do People with Color Blindness Confuse?

José Antonio López Guerrero uses his RNE program “Entre Probetas”, to introduce us to the complex and curious psychology of color. How do people diagnosed with severe color blindness relate to colors and the language for cataloguing them?

Are there different forms of color blindness? If a person with color blindness names a color correctly, does this mean they are seeing it in the same way as someone with normal vision? These and other similar questions are often answered incorrectly. This was the main reason for writing the book “Psicología del Color y Daltonismos: Principios y Aplicaciones” (The Psychology of Color and Color Blindness: Principles and applications”.

The book offers scientific -but comprehensible- information on the chromatic world of color blindness and, in particular, how sufferers use the names of colors. A team led by Julio Lillo has been researching this issue over recent years, publishing their results in the journal “Color Research and Application”.

This research at Madrid’s Complutense University found that common color blindness confusions -such as those between yellows and reds, or between greens and reds- depend on the type of stimulus. A person with color blindness may not be able to differentiate between yellow and red lights, but might be able to distinguish the red of a can of Coca-Cola and the yellow of a banana.

This research has reached two main conclusions. Firstly, people with color blindness often use the same color names as normally sighted people, even though they might be seeing different colors. Secondly, people with color blindness use color names better when using “related colors” and when the strength of the stimulus increases.

The researchers have developed a model for predicting use of chromatic categories that can explain over 90% of color naming in people with a severe form of color blindness –protanopia or deuteranopia-. In addition to incorporating the perceived clarity of the surface stimulus, this model also assumes that people with color blindness receive a different type of information from strong stimuli than from weak stimuli.

If you want to listen to the original content (in Spanish only), You can enjoy it here.

José Antonio López Guerrero

Microbiology Professor at UAM (Universidad Autónoma de Madrid). Researcher and Director of the Scientific Culture Department of the Severo Ochoa Molecular Biology Center