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Frank Crystalline

#63aacb
Notes

Frank Crystalline (#63AACB) 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 (199°, 50%, 59%) 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 orange. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#63aacb
RGB
rgb(99, 170, 203)
HSL
hsl(199, 50%, 59%)
HWB
hwb(199 39% 20%)
OKLCH
oklch(70.4% 0.086 229.7)
P3
color(display-p3 0.4541 0.6597 0.7827)
HSV
hsv(199, 51%, 80%)
LAB
lab(66.30% -13.19 -23.68)
LCH
lch(66.30% 27.11 240.89)
CMYK
cmyk(51%, 16%, 0%, 20%)

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.

Crystalline
noun

Water of exceptional clarity — particularly the crystalline mountain springs of Alpine and Andean rivers. Crystalline color refers to a fresh-emerged spring water in a marble basin at Plitvice Lakes: a soft, slightly cool pale blue with the optical clarity of mineral-saturated 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.

#63aacb
Original
#99a8cd
Protanopia
#8a9ccb
Deuteranopia
#26b3b5
Tritanopia
#9d9d9d
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
2.58:1
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
8.14:1

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
##63AACB
Display P3
Display P3
color(display-p3 0.4541 0.6597 0.7827)
P3 has subtle headroomOKLCH chroma 0.086

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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