Cold Diabase
Cold Diabase (#0E0D2D) is a deep blue with an earthy character. It leans grounded and natural, the kind of color that plays well with wood, clay, linen, and warm neutrals. Its HSL profile (242°, 55%, 11%) 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 yellow. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Old English ceald, of low temperature — used as a color modifier since the medieval period for hues with a slight blue or blue-green shift, even within otherwise neutral grays. Cold gray, cold white: the optical impression of a low-temperature reflective surface. Sits in the neutral-and-cool corner alongside icy.
French diabase, traverse-mineral — the deep-cool-gray fine-grained intrusive-igneous rock of dyke-and-sill emplacement, particularly the Triassic-and-Jurassic Newark-Basin diabase of the New York-and-New Jersey Palisades. Diabase color refers to a New-Jersey-Palisades Newark-Basin diabase cliff-face in midday sun: a dark cool-gray with the matte finish of plagioclase-and-pyroxene intrusive-igneous fine-grained rock.
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 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.