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Vivid Ābī

#21eff4
Notes

Vivid Ābī (#21EFF4) is a true cyan 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 (181°, 91%, 54%) 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.

HEX
#21eff4
RGB
rgb(33, 239, 244)
HSL
hsl(181, 91%, 54%)
HWB
hwb(181 13% 4%)
OKLCH
oklch(86.6% 0.144 197.6)
HSV
hsv(181, 86%, 96%)
LAB
lab(86.30% -43.27 -15.60)
LCH
lch(86.30% 46.00 199.82)
CMYK
cmyk(86%, 2%, 0%, 4%)

Etymology

Vivid
adjective

From the Latin vividus, full of life — used as a color modifier since the late sixteenth century for hues that read as luminous and saturated. Vivid red, vivid blue: the implication is that the color appears almost lit from within, with the optical brightness of a high-chroma surface in good light. Sits at the bright-bucket center alongside bright and electric.

Ābī
noun

The Persian word for water-colored (from āb, water) — used for the saturated turquoise-blue of Iranian tile and the ābī glaze of Safavid pottery. The color refers to a polished ābī tile from Isfahan's Imam Mosque: a saturated, slightly cool deep blue-green with the high gloss of fired faience.

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 explore

Harmonies

Accessibility

Color-vision simulation

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.

#21eff4
Original
#dde3f5
Protanopia
#c2d0f5
Deuteranopia
#00f8f0
Tritanopia
#c4c4c4
Achromatopsia
WCAG contrast

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.

The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
Failon White
1.43:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AAAon Black
14.72:1

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