Authoritative Knight Hibiscus
Authoritative Knight Hibiscus (#EF351D) is a true red with a neon character. It sits at the high-saturation edge of its family. Use it sparingly, as signage, accent, or highlight against darker surfaces. Its HSL profile (7°, 87%, 53%) places it in the highly saturated band at a mid lightness. Best used in small doses, like logos, CTAs, focus rings, or highlight text, where its saturation becomes a feature rather than noise. For a confident two-color system, pair it with its complementary cyan. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Latin auctōritāt-, authority — adjectival suffix -ive. As a color modifier, authoritative implies a saturated-and-formal-imperative quality where the hue carries decisional weight and institutional credibility. Sits at the bold-and-authoritative end of the grid, parallel to commanding and magisterial in usage.
Old English cniht, young-man / knight. As a color modifier, knight implies a chivalric-and-armored quality, the visual register of English-Plantagenet-and-French-Capetian hand-forged plate-armor-and-shield-and-lance-and-pennant knightly-and-chivalric surfaces under English-Plantagenet-and-French-Capetian chivalric-armored-knight ceremonial-court light. Sits at the modifier-and-cultural end of the grid, parallel to squire and page in usage.
Hibiscus rosa-sinensis — the showy mallow of Pacific gardens, the Hawaiian state flower, the source of the deep red sorrel tea sold across West Africa as bissap. The color refers to a fully open hibiscus petal at midday: a hot, slightly magenta red with the velvet texture of a single-day bloom. By evening the same flower has wilted; by morning it's gone.
Closest matches
The nearest named color in three reference sources, ranked by perceptual distance (ΔE76 in CIELAB). ΔE < 1 is imperceptible to most viewers; ΔE > 10 is clearly different. When two sources point to the same hex they’re merged into one tile; click any to open that color’s page.
Variations
Click any swatch to exploreHarmonies
Accessibility
How this color appears to viewers with the four major color-vision-deficiency types. Computed via the Machado (2009) physiologically-based model. If a tile matches the original, the color reads the same to that viewer.
The color used as foreground text against pure white and pure black, with the contrast ratio and WCAG 2.1 grade. Aim for AA (4.5:1) for body text and AA Large (3:1) for 18 pt+ headlines; AAA (7:1) is the gold standard for long-form reading surfaces.
Wide gamut
The CSS Color 4 wide-gamut form of this color. Both swatches render the same color on every display — the P3 form only diverges from sRGB when a designer pushes channels outside sRGB's reach.
This color is chromatic enough that authoring it as P3 native (instead of clamping to sRGB) gives a perceptibly more saturated render on wide-gamut displays — modern Macs, iPhones, iPads, and most recent OLED laptops.