Sure Opus Ocean
Sure Opus Ocean (#53E0E8) is a true cyan with a vibrant character. It holds its own as a focal accent, carrying visual weight without tipping into neon territory. Its HSL profile (183°, 76%, 62%) 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 red. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Old French seur, certain — used as a color modifier since the medieval period for hues that read as confident and stable. Sure red, sure blue: moderate saturation combined with optical commitment. Sits at the crisp-bucket center alongside steady and true.
Latin opus, work-or-composition. As a color modifier, opus implies a Latin-work-and-Magnum-Opus-and-Opus-Dei quality, the visual register of Magnum-Opus-and-musical-opus-number hand-Latin-work-and-Magnum-Opus-and-Opus-Dei Magnum-Opus-and-musical-opus-number-and-medieval-cathedral-opus opus-and-Latin-work surfaces under Magnum-Opus-and-musical-opus-number-and-medieval-cathedral-opus monastic-scriptorium-and-medieval-cathedral-fabric craft-and-composition-light. Sits at the modifier-and-Latin end of the grid, parallel to magnus and ergo in usage.
The body of saltwater that covers seventy percent of Earth's surface — a single connected mass divided by convention into Atlantic, Pacific, Indian, Southern, and Arctic. The color refers to the average reflectance of mid-depth temperate ocean: a saturated, slightly green-shifted deep blue with the optical depth of a body of water that absorbs all light below the photic zone. Deeper than mediterranean, cooler than peacock.
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.