The color sphere is a three-dimensional model mapping hue, brilliance, and saturation simultaneously, with white and black at the poles

Itten (following Runge) organizes the full color universe as a sphere: the equatorial band holds the 12 pure saturated hues; white at the north pole, black at the south pole; tints (hue+white) in northern hemisphere, shades (hue+black) in southern; desaturated mixtures (hue+complementary) toward the gray axis at center. The sphere makes several relationships visible: (1) any two diametrically opposite points across the center are complementary — including tints and shades (pink’s complement is dark green); (2) cross-sections at any level reveal saturation scales; (3) vertical meridian sections through any complementary pair show tint-to-shade progressions; (4) five principal transition paths exist between any two colors: two horizontal (via spectrum in either direction), two vertical (via white or black), one diagonal (via gray). This model is equivalent to modern HSL/HSV color spaces.

Examples

HSL in code: H = equatorial position, L = north-south axis (0=black, 0.5=equatorial pure, 1=white), S = distance from center axis. In GLSL: hsl2rgb(vec3(hue, saturation, lightness)).

Assessment

Identify where ‘brown’ lives in the color sphere (it is a dark shade of orange); find the complementary of ‘pink’ using the sphere model; describe the difference between the diagonal path and the horizontal path between two complementaries.