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Lucid Tarn

#51ecf9
Notes

Lucid Tarn (#51ECF9) 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 (185°, 93%, 65%) 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 red. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#51ecf9
RGB
rgb(81, 236, 249)
HSL
hsl(185, 93%, 65%)
HWB
hwb(185 32% 2%)
OKLCH
oklch(86.8% 0.128 203.2)
HSV
hsv(185, 67%, 98%)
LAB
lab(86.29% -36.00 -18.16)
LCH
lch(86.29% 40.32 206.76)
CMYK
cmyk(67%, 5%, 0%, 2%)

Etymology

Lucid
adjective

Latin lūcidus, clear / bright — derived from lūx (light). As a color modifier, lucid implies a clear-and-readable quality where the hue is unambiguous and free of optical clutter. Sits at the crisp-and-clear end of the grid, parallel to pellucid and plain in usage.

Tarn
noun

A small mountain lake — particularly the cwm (cirque) lakes of the British Lake District, the Welsh hills, and the Norwegian peaks. From the Old Norse tjörn. Tarn color refers to a fresh-water tarn at Stickle Tarn in Cumbria: a saturated, slightly cool deep blue with the optical depth of cold-water mountain pool.

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.

#51ecf9
Original
#dae2fa
Protanopia
#c1d0fa
Deuteranopia
#00f5f0
Tritanopia
#cccccc
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
1.43:1
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
14.72:1

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