Buttressed Indranīla
Buttressed Indranīla (#3166B9) is a true azure with a cool character. It leans cool, sitting on the blue, green, and violet side of the wheel. Quiet and dependable, a fit for product UI and data visualization. Its HSL profile (217°, 58%, 46%) places it in the balanced band at a mid lightness. It works across type, buttons, and borders, saturated enough to feel deliberate but balanced enough to not fight the rest of the palette. 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 bouterez, thrusting-mass — past-participle of buttress, derived from bouter (to thrust). As a color modifier, buttressed implies a saturated-and-architecturally-supported quality, the deep-rich color of Gothic-Cathedral flying-buttress-and-rib-vault stone-architecture. Sits at the bold-and-fortified end of the grid, parallel to fortified and reinforced.
The Sanskrit word for sapphire — combining Indra (the king of the gods) and nīla (deep blue). Used in classical Hindu jewelry vocabulary for the deep-blue gems of Indian royal regalia. The color refers to a faceted Kashmir indranīla: a saturated, slightly cool deep blue with the gem's signature internal velvet.
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.