Foundational Crypt
Foundational Crypt (#0E0D3B) is a deep blue 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 (241°, 64%, 14%) 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
Latin fundātiō, foundation — adjectival suffix -al. As a color modifier, foundational implies a neutral-and-base-and-supporting quality where the hue carries the visual register of Bauhaus-and-Mondrian-De-Stijl foundational-and-base-supporting-color theoretical-color-system. Sits at the neutral-and-foundational end of the grid, parallel to primary and essential in usage.
Greek kryptē, hidden-chamber — the deep-cool-gray underground-chamber of medieval European cathedral-and-basilica architecture, particularly the San-Marco-Venice and Santa-Cruz-Coimbra royal-crypt chambers. Crypt color refers to a Saint-Denis-Basilica royal-crypt chamber face in candlelight: a dark cool-gray with the matte finish of Île-de-France-Lutetian-limestone hand-quarried 12th-century Capetian-royal-mausoleum architecture.
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.