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Frank Alpine

#63e9f0
Notes

Frank Alpine (#63E9F0) 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 (183°, 82%, 66%) 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
#63e9f0
RGB
rgb(99, 233, 240)
HSL
hsl(183, 82%, 66%)
HWB
hwb(183 39% 6%)
OKLCH
oklch(86.3% 0.117 200.0)
P3
color(display-p3 0.5344 0.9023 0.9331)
HSV
hsv(183, 59%, 94%)
LAB
lab(85.61% -34.34 -14.40)
LCH
lch(85.61% 37.24 202.75)
CMYK
cmyk(59%, 3%, 0%, 6%)

Etymology

Frank
adjective

From the Old French franc, free, sincere — used as a color modifier since the seventeenth century for hues that read as direct and unhedged. Frank red, frank brown: moderate-to-high saturation combined with optical directness. Sits at the crisp-bucket alongside direct and honest.

Alpine
noun

Of the Alps, the European mountain range — and the saturated blue of Alpine lake water (Lake Geneva, Lake Como, Lake Brienz) fed by glacier-melt. Alpine color refers to Lake Brienz at midday: a saturated, slightly cool deep blue with the optical clarity of glacier-fed alpine lake water.

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.

#63e9f0
Original
#dadff1
Protanopia
#c3cff1
Deuteranopia
#00f1eb
Tritanopia
#cdcdcd
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
1.45:1
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
14.44:1

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
##63E9F0
Display P3
Display P3
color(display-p3 0.5344 0.9023 0.9331)
P3 has subtle headroomOKLCH chroma 0.117

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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