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Dependable Cascade

#21b3db
Notes

Dependable Cascade (#21B3DB) 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°, 74%, 49%) 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
#21b3db
RGB
rgb(33, 179, 219)
HSL
hsl(193, 74%, 49%)
HWB
hwb(193 13% 14%)
OKLCH
oklch(71.3% 0.126 222.5)
P3
color(display-p3 0.3363 0.6917 0.8422)
HSV
hsv(193, 85%, 86%)
LAB
lab(67.78% -22.48 -30.37)
LCH
lch(67.78% 37.79 233.49)
CMYK
cmyk(85%, 18%, 0%, 14%)

Etymology

Dependable
adjective

Latin dē-pendere, to hang from — adjectival suffix -able. As a color modifier, dependable implies a clear-and-trustworthy-and-consistent quality where the hue carries the visual register of consistently-performing-and-counted-on design-element. Sits at the crisp-and-honest end of the grid, parallel to reliable and trustworthy 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.

#21b3db
Original
#9cafdd
Protanopia
#849edb
Deuteranopia
#00bfc0
Tritanopia
#979797
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
2.46:1
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
8.54:1

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
##21B3DB
Display P3
Display P3
color(display-p3 0.3363 0.6917 0.8422)
P3 has subtle headroomOKLCH chroma 0.126

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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