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Heartening Cascade

#21a499
Notes

Heartening Cascade (#21A499) is a true cyan 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 (175°, 66%, 39%) 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
#21a499
RGB
rgb(33, 164, 153)
HSL
hsl(175, 66%, 39%)
HWB
hwb(175 13% 36%)
OKLCH
oklch(65.0% 0.107 186.1)
P3
color(display-p3 0.3103 0.6338 0.5988)
HSV
hsv(175, 80%, 64%)
LAB
lab(60.93% -35.96 -4.00)
LCH
lch(60.93% 36.18 186.35)
CMYK
cmyk(80%, 0%, 7%, 36%)

Etymology

Heartening
adjective

Old English heorte (heart) — present-participle of hearten. As a color modifier, heartening implies a clear-and-uplifting-and-encouraging quality where the hue carries the visual register of cheerful-encouraging color-tone. Sits at the crisp-and-cheerful end of the grid, parallel to welcoming and cheerful in usage.

Cascade
noun

A waterfall of moderate size — particularly the Cascade Range of waterfalls along the Pacific Northwest's Columbia River Gorge. Cascade color refers to the white-and-blue of falling water at Multnomah Falls: a soft, slightly cool pale blue-white with the optical complexity of mist-and-water in motion.

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.

#21a499
Original
#9b9a99
Protanopia
#8a8e9a
Deuteranopia
#00a8a0
Tritanopia
#878787
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).
AA Largeon White
3.07:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AAon Black
6.83:1

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
##21A499
Display P3
Display P3
color(display-p3 0.3103 0.6338 0.5988)
P3 has subtle headroomOKLCH chroma 0.107

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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