Tetrahedral Avian Colorspace

The visual systems of birds, many other reptiles, and many fishes include four color sensitive retinal cone types. As a consequence, their color vision is more complex than human color vision. We have developed new computation tools that will allow users to understand the complexity of color.

Stoddard and Prum (2008) produced a MATLAB program called TETRACOLORSPACE (TCS) that quantitatively models the color stimulus produced by a reflectance spectrum. The program can analyze either violet and ultravolet cone type avian visual systems, or use any four cone sensitivity functions input by the user. The tool also provides various quantitative analysis and graphical tools for describing color stimulus variation and diversity. Details of the analysis are available in Stoddard and Prum (2008) and in the TetraColorSpace Manual below

You can Download the latest version of TetraColorSpace and the User’s Manual here:


Stoddard, M. C. and Prum, R. O. 2008. Evolution of avian plumage color in a tetrahedral color space: a phylogenetic analysis of New Word buntings. American Naturalist 171: 755-76.

Stoddard, M. C. and Prum, R. O. 2011. How colorful are birds? Evolution of the avian plumage color gamut. Behavioral Ecology In press. doi:10.1093/beheco/arr088.