Ominous Aizu
Ominous Aizu (#171550) is a deep blue 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 (242°, 58%, 20%) 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 ōminōsus, full of foreboding — derived from omen. As a color modifier, ominous implies a deep-and-threatening atmospheric-foreboding quality, the dark cool-gray of Goyaesque storm-laden sky. Sits at the deep-and-threatening end of the grid, parallel to foreboding and menacing in tone.
Japanese feudal domain (Aizu-han) of the Edo period — a samurai region in modern Fukushima famous for aizu-momen, the indigo-dyed cotton woven by samurai-class women during the Tokugawa shogunate's lean years. Aizu color refers to a freshly aizu-momen-woven indigo cotton: a saturated, slightly cool deep blue-violet with the matte finish of multi-bath natural indigo on hand-spun cotton.
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.
Wide gamut
The CSS Color 4 wide-gamut form of this color. Both swatches render the same color on every display — the P3 form only diverges from sRGB when a designer pushes channels outside sRGB's reach.
Moderately saturated colors gain a small bump in P3 — the difference is usually visible side-by-side on wide-gamut hardware but won't change the character of the color.