Steadfast Indigotin
Steadfast Indigotin (#3163CA) 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 (220°, 61%, 49%) 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 English stede-fæst, fixed in place — sharing root with German stetig. As a color modifier, steadfast implies a saturated-and-unwavering quality where the hue maintains its visual character without modulation. Sits at the bold-and-firm end of the grid, parallel to unwavering and firm in usage.
The chemical name for the indigo molecule (C₁₆H₁₀N₂O₂) — extracted from Indigofera dye plants and chemically synthesized industrially since 1897 (BASF's process). Indigotin names the pure pigment distinct from the unpurified plant-dye indigo. The color refers to fresh indigotin-dyed cotton: a saturated, slightly cool deep blue.
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.