Steely Cathedral
Steely Cathedral (#0C1129) 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 (230°, 55%, 10%) 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 amber. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
An adjectival form of steel — used as a color modifier since the eighteenth century for hues with the slight blue-gray of tempered or polished steel. Steely gray, steely blue: moderate-to-low saturation combined with the optical impression of metallic surface. Sits in the neutral-and-cool corner alongside cold.
The interior color of an aging Gothic cathedral — limestone darkened by centuries of candle smoke, incense, and city soot. The color refers to the upper walls of Notre-Dame de Paris before the 2019 fire and restoration: a soft, slightly muted dark gray with the matte finish of weathered porous stone. Cooler than smoke, warmer than slate, with the architectural weight of a building type whose interiors are read primarily in shadow.
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.