Pulsing Bluet
Pulsing Bluet (#669BFE) 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 (219°, 99%, 70%) 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
The progressive participle of pulse, to throb. Used as a color modifier for hues that read as if they were alternating between two states of luminance — the vibration of a high-saturation color against a contrasting background. Sits in the bright-bucket center alongside electric, with the implication of optical motion rather than static luminance.
Houstonia caerulea, the small wildflower of New England meadows and Appalachian roadsides — four-petaled, no taller than a thumb, blooming in spring carpets. Sometimes called Quaker ladies for the bonnet-like flower shape. The color refers to a fresh bluet flower at peak bloom: a soft, slightly green-shifted pale blue with the matte finish of a tiny corolla. Lighter than bluebell, cooler than periwinkle, with the early-spring association of a flower that opens before the trees leaf.
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.