Figure 1. Geomtric distances equal perceptual distances. Palette in CAM16-UCS perceptually uniform color space [1].
(*): While ColorHedra palettes are optimized for common types of color vision deficiency, good designs combine color with other visual cues (e.g. labels, arrows, textures).
// sortBy: "h" for hue, "c" for chroma, "l" for lightness const hexCodes = colorhedraPal( 7, // nColors "h" // sortBy );
FAQs
Why is there only a single palette option for each palette size?
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ColorHedra is not a color palette generator. Instead, ColorHedra palettes are pre-calculated optimal solutions so you can skip the endless fiddling of trying to get the perfect combination. Please refer to the Methods page for more details.
What is color vision deficiency?
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Color vision deficiency, or color blindness, is a condition which alters the way the eye perceives colors and affects very approximately 1 in 12 men and 1 in 200 women [2]. ColorHedra palettes were designed to accommodate the most common types of color vision deficiency, which include the red-green deficiencies deuteranomaly, deuteranopia, protanomaly, and protanopia. While still providing some benefit, these palettes were not specifically designed for the much rarer types of color vision deficiency, such as tritanomaly, tritanopia and achromatopsia. Color vision deficiency simulations on this site uses the method from Machado et al. [3].
What are perceptually uniform color spaces?
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Perceptually uniform color spaces, such as CAM16-UCS [1], are designed so that geometric distances between colors are proportional to their percieved differences. This characteristic isn't true for the standard RGB "cube", which contains distortions. ColorHedra palettes were developed using CAM16-UCS in order to best match how people perceive color.
Some colors blend too much into the background for my liking. What should I do?
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Try adding a thin border around components in order to increase their contrast with the background (e.g. black borders for a white background). High differences in lightness between colors help people with color vision deficiencies because lightness perception is usually less affected than color perception. Alternatively, just don't use that color.
Where can I use ColorHedra palettes?
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ColorHedra palettes are free to use anywhere. Go nuts!
References
1.
Li C, Li Z, Wang Z, Xu Y, Luo MR, Cui G, Melgosa M, Brill MH, Pointer M. Comprehensive color solutions: CAM16, CAT16, and CAM16‐UCS. Color Research & Application. 2017 Dec;42(6):703-18.
2.
Almustanyir A. A Global Perspective of Color Vision Deficiency: Awareness, Diagnosis, and Lived Experiences. InHealthcare 2025 Aug 17 (Vol. 13, No. 16, p. 2031). MDPI.
3.
Machado GM, Oliveira Neto MM, Fernandes LA. A physiologically-based model for simulation of color vision deficiency. IEEE transactions on visualization and computer graphics. Los Alamitos. Vol. 15, no 6 (2009 Nov./Dec.), p. 1291-1298. 2009.