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Heartening Tide

#21708b
Notes

Heartening Tide (#21708B) is a deep cyan with a jewel character. It carries the deep, saturated richness of a gemstone. Authoritative and slightly formal, it works well for type and heavy UI elements. Its HSL profile (195°, 62%, 34%) places it in the balanced band at a dark lightness. It works well as a headline, icon, or deep background in an otherwise light layout, pairing cleanly with cream, bone, and warm neutrals. 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
#21708b
RGB
rgb(33, 112, 139)
HSL
hsl(195, 62%, 34%)
HWB
hwb(195 13% 45%)
OKLCH
oklch(51.1% 0.085 225.4)
P3
color(display-p3 0.2245 0.4330 0.5342)
HSV
hsv(195, 76%, 55%)
LAB
lab(43.91% -13.97 -21.57)
LCH
lch(43.91% 25.70 237.07)
CMYK
cmyk(76%, 19%, 0%, 45%)

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.

Tide
noun

The slow flow of seawater driven by lunar gravity — the daily cycle of high to low and back. Tidal and tide used as a color refer to the deep blue-green of coastal water at mid-tide on an overcast day: a soft, slightly muted blue-green with the optical complexity of water in motion. Cooler than reef, deeper than seafoam, with the ecological weight of a force that has shaped every coastline on Earth.

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.

#21708b
Original
#616e8c
Protanopia
#53638b
Deuteranopia
#007879
Tritanopia
#616161
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).
AAon White
5.59:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AA Largeon Black
3.76:1

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
##21708B
Display P3
Display P3
color(display-p3 0.2245 0.4330 0.5342)
P3 has subtle headroomOKLCH chroma 0.085

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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