Sovereign Cobaltite
Sovereign Cobaltite (#155DB4) 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 (213°, 79%, 39%) places it in the highly saturated band at a mid 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 orange. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Old French soverain, supreme — derived from Latin super (above). As a color modifier, sovereign implies a saturated-and-royal-supremacy quality where the hue carries imperial-ruling-class register. Sits at the bold-and-imperial end of the grid, parallel to regal and imperial in tone.
A cobalt-arsenic-sulfide mineral — the principal historical source of cobalt for ceramic and pigment use. Mined principally in Cobalt, Ontario (the source of the modern cobalt-mining industry's name). The color refers to a polished cobaltite crystal: a soft, slightly cool deep blue-silver with the metallic finish of crystallized cobalt 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.