Abstract: A color separation device or chamber in the form of a regular rhombic dodecahedron. Each interior face or plane comprises a specifically colored reflecting surface and is arranged in such a manner that each interior plane expresses the given order of reflection suggested by a syllogistic algorithm. The conventional or regular dodecahedron is circumscribed by a sphere. The chamber is suitable as a cell for liquid or gas in an analysis instrument such as a spectrophotometer. Such a chamber may be equipped with inlet and outlet ports, light sources and light sensors at appropriate locations in the interior faces.