During the Medieval era, various Islamic scholars made important discoveries in color science. Breaking with the theories of Aristotle, al-Kindi proposed that it is not the medium that produces color, but the object, by blocking light. Similarly, Ibn Rushd and Ibn al-Haytham promoted the role of light for color vision from being a mere catalyst to the very object of sight. And instead of the classical one-dimensional color order, gradually a two-dimensional color order emerged in the writings of Ibn Sina and al-Tusi. Further, Nishaburi described the first partial hue scale. Other breaks with classical dogma are found in descriptions of the rainbow, and in publications of color mixtures. In other aspects, Islamic scholars stayed more firmly in the Aristotelian framework. They still confused lightness and hue differences, and they did not fully break with the idea that all colors can be produced by mixing black and white. (c) 2013 Wiley Periodicals, Inc. Col Res Appl, 40, 5-16, 2015