Royal Kelp
Royal Kelp (#218630) is a deep green with a jewel character. It carries the deep, saturated richness of a gemstone. Authoritative and slightly formal, it works well for type and heavy UI elements. Its HSL profile (129°, 60%, 33%) places it in the balanced band at a dark lightness. It works well as a headline, icon, or deep background in an otherwise light layout, pairing cleanly with cream, bone, and warm neutrals. For a confident two-color system, pair it with its complementary violet. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
The blue of European royal court dress and regalia from the late seventeenth century forward — the color of British peers' robes, French royal sashes, the lining of the crown-jewel cases. The color refers to a saturated, slightly violet-shifted blue with the matte finish of velvet or melton wool dyed to maximum intensity: deeper than cornflower, warmer than ultramarine, with the heraldic weight of a color reserved for monarchs and the official Crown.
Large brown algae of the order Laminariales — the giant Macrocystis pyrifera of California's coast and the smaller Laminaria digitata of British shores. Kelp color refers to fresh kelp washed up on a Pacific beach at low tide: a deep, slightly muted dark green-brown with the satin finish of marine alga.
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.
Moderately saturated colors gain a small bump in P3 — the difference is usually visible side-by-side on wide-gamut hardware but won't change the character of the color.