Booming Capri
Booming Capri (#3175F4) is a true azure with a neon character. It sits at the high-saturation edge of its family. Use it sparingly, as signage, accent, or highlight against darker surfaces. Its HSL profile (219°, 90%, 57%) 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
Imitative-onomatopoeic origin — present-participle of boom, sharing root with Dutch bommen. As a color modifier, booming implies a saturated-and-loud-and-confident quality where the hue announces itself with full visual amplitude. Sits at the bold-and-resonant end of the grid, parallel to resounding and thunderous.
The Italian island in the Bay of Naples whose Blue Grotto — a sea cave where light enters through an underwater opening — turns the water inside an electric, otherworldly blue. The color refers to the water of the Grotta Azzurra: a saturated, slightly green-shifted electric blue with the optical clarity of light filtered through twenty meters of seawater. Brighter than aqua, more chromatic than turquoise, with the tourist-destination association of a single specific cave.
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.