Many named colors start with H across the major catalogs — Wikipedia's color lists, Crayola's historical crayon catalog, Pantone's archives, the xkcd Color Survey, heritage paint references, and brand color guides. This page currently lists 31 notable H-color names. Two CSS named-color keywords start with H: honeydew (#F0FFF0, a near-white with a faint green tint) and hotpink (#FF69B4, a vivid warm pink). Both were inherited from the X11 color set when the W3C standardized the CSS named-color list.

Several strong candidates. Harvard Crimson is Harvard's school color; the value shown, #A41034 (Pantone 187 U / 1807 C), is the crimson published by Harvard Athletics and Harvard Business School, while the central Harvard University identity uses a closely related #A51C30 (Pantone 201); students officially adopted crimson as the university color in 1910 after a tradition dating to 1858 crew-team scarves. Honolulu Blue has been the primary color of the Detroit Lions NFL franchise since the team moved to Detroit from Portsmouth, Ohio in 1934 (Pantone PMS 7462 C, #0076B6). Honeysuckle was Pantone's Color of the Year for 2011 (PANTONE 18-2120). Han Blue and Han Purple are synthetic barium copper silicate pigments developed in ancient China and used from the Western Zhou period (1045–771 BC) through the Han dynasty (c. 220 AD). Hooker's Green is the named-after-the-mixer watercolor pigment that William Hooker (1779–1832) created around 1815 for botanical illustration at the Horticultural Society of London. Hansa Yellow is the family of synthetic arylide yellow pigments first synthesized in 1909 by Hermann Wagner at Hoechst AG.

Honeydew's CSS-specified value is RGB(240, 255, 240), HSL 120°/100%/97%. Although technically in the green hue family (hue angle 120°), the 97% lightness puts it essentially at near-white — its faint green tint is barely perceptible on a typical screen, especially against any non-white background. This catalog applies a near-white rule: extremely pale, low-chroma colors classify under the White shade family by default unless the hue stays visually dominant. Honeydew's hue doesn't remain dominant at that lightness, so it joins the white family. The CSS hex value itself is unchanged (#F0FFF0) — only the shade-family categorization differs from a strict "by hue angle" classification.

Yes. Per the Asian Art Museum, Wikipedia "Han purple and Han blue," and peer-reviewed analyses (FitzHugh and Zycherman 1983 and 1992; Berke 2002, 2007), both pigments — synthetic barium copper silicates with the formulas BaCuSi4O10 (Han blue) and BaCuSi2O6 (Han purple) — have been identified on Chinese artifacts dating to the Western Zhou period (1045–771 BC) and the Warring States period (475–221 BC), well before the Han dynasty (206 BC–220 AD) that gave them their conventional Western names. The Asian Art Museum notes directly that the pigments are "misnamed, since both colors have been found well before the Han dynasty in China, perhaps as early as the Western Zhou dynasty." In 1993, Han blue was discovered to occur naturally as the rare mineral effenbergerite — but for ancient artifacts, the pigment is unambiguously synthetic. The digital hex values cataloged here are public-database approximations of inorganic pigments whose actual appearance varies with grain size, binder, and substrate; they are not authoritative reproductions.

Hooker's Green is named after William Hooker (1779–1832), a British botanical illustrator who served as the official artist of the Royal Horticultural Society (then called the Horticultural Society of London) from 1812 until his retirement in 1820. Per Wikipedia and Winsor & Newton, around 1815 Hooker mixed Prussian Blue (the first stable synthetic blue pigment, discovered c. 1706) and Gamboge (a yellow resin pigment from Garcinia trees) to produce a deep green for the foliage in his detailed watercolor illustrations. Because gamboge is fugitive, the original mixture could fade in sunlight; modern Hooker's Green paints use more lightfast pigment blends that vary by manufacturer. He is different from the more-famous William Jackson Hooker (1785–1865), who was the first director of the Royal Botanic Gardens at Kew — the two were contemporaries and the namesake is frequently misattributed. The pigment name carries the apostrophe ("Hooker's Green"); the Oxford English Dictionary gives an origin date of 1850–1855 for the color name.

For the two CSS-named H-colors — honeydew (#F0FFF0) and hotpink (#FF69B4) — yes. The W3C CSS Color Module specification fixes the exact sRGB values, and every modern browser renders them identically. For institutional brand colors, this page uses the value each brand itself publishes as authoritative: Harvard Crimson #A41034 (Pantone 187 U / 1807 C) per Harvard Business School's Identity Guidelines and Harvard Athletics — the central university identity uses a related #A51C30 (Pantone 201); Honolulu Blue #0076B6 (Pantone PMS 7462 C) per the Detroit Lions' brand guide and the official NFL Record and Fact Book. For Pantone references like Honeysuckle (PANTONE 18-2120, 2011 Color of the Year), the cataloged hex is an sRGB approximation of a textile or coated-paper swatch standard; the digital value varies slightly across third-party catalogs. For historical pigments like Han Blue, Han Purple, Hansa Yellow, and Hooker's Green, the hex is a public-database approximation of a physical pigment whose actual appearance depends on grain, binder, lighting, and substrate — no single sRGB swatch is the universal reproduction of the pigment.