Refulgent Crater
Refulgent Crater (#6489FE) is a true 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 (226°, 99%, 69%) 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 amber. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Latin refulgēns, shining-back — present-participle of refulgere, sharing root with fulgor (lightning). As a color modifier, refulgent implies a saturated-and-reflective-shining quality, the bright color of polished-bronze-and-armor reflective-surface mid-day-sun reflection. Sits at the bright-and-saturated end of the grid, parallel to effulgent and resplendent in usage.
Crater Lake — the deepest lake in the United States, formed in the caldera of Mount Mazama (collapsed 7,700 years ago) in Oregon. The lake is famously deep blue. Crater refers to mid-depth Crater Lake water at midday: a saturated, slightly cool very deep blue with the optical depth of the world's clearest temperate lake.
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.