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Caffeinated Tarn

#15e4f0
Notes

Caffeinated Tarn (#15E4F0) 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 (183°, 88%, 51%) 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
#15e4f0
RGB
rgb(21, 228, 240)
HSL
hsl(183, 88%, 51%)
HWB
hwb(183 8% 6%)
OKLCH
oklch(83.7% 0.140 201.7)
HSV
hsv(183, 91%, 94%)
LAB
lab(82.88% -40.07 -18.65)
LCH
lch(82.88% 44.20 204.95)
CMYK
cmyk(91%, 5%, 0%, 6%)

Etymology

Caffeinated
adjective

Modern French caféine — past-participle of caffeinate. As a color modifier, caffeinated implies a saturated-and-jumpy-and-active quality, the bright color of Red-Bull-and-Monster energy-drink-can label-design saturated-and-energizing palette. Sits at the bright-and-active end of the grid, parallel to jazzed and wired 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.

#15e4f0
Original
#d1d9f1
Protanopia
#b7c6f1
Deuteranopia
#00ede7
Tritanopia
#b9b9b9
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
1.57:1
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
13.39:1

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