Towering Dumortierite
Towering Dumortierite (#031F5B) is a deep azure 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 (221°, 94%, 18%) places it in the highly saturated band at a dark lightness. Best used in small doses, like logos, CTAs, focus rings, or highlight text, where its saturation becomes a feature rather than noise. 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
Old French tour, tower via Latin turris — present-participle of tower. As a color modifier, towering implies a deep-and-vertical-and-architectural quality, the dark cool-gray of Salisbury-Cathedral-and-Chartres-Cathedral spire-and-tower against the sky. Sits at the deep-and-architectural end of the grid, parallel to imposing and looming.
An aluminum-borate-silicate mineral — saturated deep blue, mined principally in Madagascar, Brazil, and Nevada. Used as ornamental stone and porcelain manufacturing additive. The color refers to a polished dumortierite cabochon: a saturated, slightly cool deep blue with the matte finish of opaque silicate mineral.
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.