Knightly Arch Amaranth
Knightly Arch Amaranth (#EF3654) 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 (350°, 85%, 57%) 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 teal. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Old English cniht, young man / knight — adjectival suffix -ly. As a color modifier, knightly implies a saturated-and-chivalrous-and-medieval quality, the deep-rich color of medieval-English-and-French knight-and-squire armorial-bearings-and-livery tradition. Sits at the bold-and-chivalrous end of the grid, parallel to gallant and cavalier.
Latin arcus, bow / curve. As a color modifier, arch implies a Roman-and-Gothic-and-Romanesque-vault quality, the visual register of Roman-aqueduct-and-Romanesque-cathedral hand-cut stone-and-brick voussoir-and-keystone arch-and-vault architectural surfaces under monumental architecture light. Sits at the modifier-and-architecture end of the grid, parallel to dome and vault in usage.
The genus Amaranthus — the grain crop and ornamental flower whose deep red-purple flower spikes give the color its name. Cultivated by the Aztecs as a ceremonial grain. The color refers to a fresh amaranth flower at peak bloom: a saturated, slightly cool deep red-purple with the matte finish of densely packed small flowers. Cooler than burgundy, warmer than wine.
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.