Rusticated Mortar
Rusticated Mortar (#4E5859) is a deep neutral with a mono character. It's a grayscale value, at home in typography, dividers, and the structural layer beneath stronger colors. Its HSL profile (185°, 7%, 33%) places it in the muted band at a dark lightness. It works as a background, hairline border, or text color in dark UI. Swap to true black when you need maximum contrast. Pair it with almost any saturated accent. It's built to sit underneath or behind stronger colors without fighting them.
Etymology
Latin rūsticātus, country-roughened — past-participle of rusticate, sharing root with rural. As a color modifier, rusticated implies a neutral-and-rough-and-rural quality, the neutral color of Italian-Renaissance-and-Florentine-palazzo rusticated-stone-base architectural-and-rough-textured ground-floor-stonework. Sits at the neutral-and-traditional end of the grid, parallel to rustic and weathered in usage.
Latin mortarium, mortar-bowl — the cool-mid-gray Portland-cement-and-sand-and-water hand-mixed binder used in modern brick-and-stone-masonry construction. Mortar color refers to a freshly applied Portland-cement mortar-joint between London-stock-brick in raking sun: a balanced cool gray with the matte finish of Type-N mortar with the characteristic Portland-cement hand-trowelled finish.
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
This color has effectively no chroma (OKLCH C = 0.013) — it’s on the grayscale axis. Hue rotations don’t change a grayscale color, so complementary, analogous, triadic, and split-complementary all reduce to the same value. They aren’t shown because four identical tiles would be misleading.
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 sits well within the sRGB cube. P3 and sRGB share the gray axis and most desaturated tones, so a P3 display renders this identically to an sRGB display.