The "Geometry" of Colours

Physicists and vision scientists recognize color as electromagnetic radiation within the visible spectrum, ranging from approximately 380 to 750 nanometers wavelength.

Isaac Newton first organized colors into a circular disc, recognizing that the spectrum of light naturally closes into a geometric circle when red meets violet.

The International Commission on Illumination (CIE) developed the XYZ color space in 1931 based on color-matching experiments that quantified how humans perceive different wavelengths.

Human retinas contain three cone cell types sensitive to different wavelength ranges, approximately corresponding to red, green, and blue light. This biological architecture determines how all humans perceive color.

Perceptual psychologists and color scientists recognize that physical color measurements don’t capture how humans actually experience color differences, leading to perceptually-based color spaces like CIELAB and CIELUV.

Color scientists and mathematicians developed numerous geometric representations of color, each emphasizing different aspects: hue-saturation-brightness cylinders, opponent-process models, perceptually-uniform spaces, and device-dependent RGB cubes.

Vision scientists recently created “olo,” an impossible color outside normal perception by using specialized techniques to stimulate cone cells in combinations natural light cannot produce. Researchers investigate what colors might exist beyond biological constraints.