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Refreshing Reservoir

#21acd3
Notes

Refreshing Reservoir (#21ACD3) is a true cyan with a vibrant character. It holds its own as a focal accent, carrying visual weight without tipping into neon territory. Its HSL profile (193°, 73%, 48%) places it in the balanced band at a mid lightness. It works across type, buttons, and borders, saturated enough to feel deliberate but balanced enough to not fight the rest of the palette. 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
#21acd3
RGB
rgb(33, 172, 211)
HSL
hsl(193, 73%, 48%)
HWB
hwb(193 13% 17%)
OKLCH
oklch(69.3% 0.122 222.9)
P3
color(display-p3 0.3241 0.6647 0.8114)
HSV
hsv(193, 84%, 83%)
LAB
lab(65.38% -21.55 -29.68)
LCH
lch(65.38% 36.68 234.01)
CMYK
cmyk(84%, 18%, 0%, 17%)

Etymology

Refreshing
adjective

Old French refreschir, to make fresh again — present-participle of refresh. As a color modifier, refreshing implies a clear-and-cool-and-revitalizing quality, the crisp color of Cornish-coast and Hebridean-island fresh-sea-air-and-cool-water revitalization. Sits at the crisp-and-cool end of the grid, parallel to fresh and bracing in usage.

Reservoir
noun

A constructed body of water — particularly the dam-impounded reservoirs of arid-region water supply: Lake Mead, Hetch Hetchy, Lake Powell. Reservoir color refers to mid-depth Lake Mead water: a saturated, slightly cool deep blue with the optical depth of stored desert water.

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.

#21acd3
Original
#96a8d5
Protanopia
#7f98d3
Deuteranopia
#00b8b9
Tritanopia
#919191
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
2.66:1
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
7.91:1

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
##21ACD3
Display P3
Display P3
color(display-p3 0.3241 0.6647 0.8114)
P3 has subtle headroomOKLCH chroma 0.122

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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