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Prismatic Heaven

#21bdf0
Notes

Prismatic Heaven (#21BDF0) 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 (195°, 87%, 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 orange. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#21bdf0
RGB
rgb(33, 189, 240)
HSL
hsl(195, 87%, 54%)
HWB
hwb(195 13% 6%)
OKLCH
oklch(74.6% 0.138 227.1)
P3
color(display-p3 0.3540 0.7304 0.9214)
HSV
hsv(195, 86%, 94%)
LAB
lab(71.56% -20.58 -35.97)
LCH
lch(71.56% 41.44 240.22)
CMYK
cmyk(86%, 21%, 0%, 6%)

Etymology

Prismatic
adjective

Greek prísma, prism — adjectival suffix -ic. As a color modifier, prismatic implies a saturated-and-multi-spectrum-decomposed quality, the bright color of crystal-prism and cut-glass-chandelier light-refraction-spectrum decomposition. Sits at the bright-and-shifting end of the grid, parallel to iridescent and spectral in usage.

Heaven
noun

The vault of the sky and (in religious vocabulary) the realm of the divine — and the saturated blue used in medieval European religious painting for sky, Mary's mantle, and divine background. Heaven color refers to a Florentine Annunciation azure background: a saturated, slightly cool deep blue with the matte finish of ultramarine pigment in tempera.

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.

#21bdf0
Original
#a2baf3
Protanopia
#88a7ef
Deuteranopia
#00ccce
Tritanopia
#a0a0a0
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
2.19:1
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
9.60:1

Wide gamut

Display P3 representation

The CSS Color 4 wide-gamut form of this color. Both swatches render the same color on every display — the P3 form only diverges from sRGB when a designer pushes channels outside sRGB's reach.

sRGB hex
sRGB hex
##21BDF0
Display P3
Display P3
color(display-p3 0.3540 0.7304 0.9214)
P3 has subtle headroomOKLCH chroma 0.138

Moderately saturated colors gain a small bump in P3 — the difference is usually visible side-by-side on wide-gamut hardware but won't change the character of the color.

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