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Frank Woad

#37c5d1
Notes

Frank Woad (#37C5D1) 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 (185°, 63%, 52%) 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 red. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#37c5d1
RGB
rgb(55, 197, 209)
HSL
hsl(185, 63%, 52%)
HWB
hwb(185 22% 18%)
OKLCH
oklch(75.6% 0.117 203.5)
HSV
hsv(185, 74%, 82%)
LAB
lab(73.12% -32.55 -16.73)
LCH
lch(73.12% 36.60 207.21)
CMYK
cmyk(74%, 6%, 0%, 18%)

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.

Woad
noun

Isatis tinctoria, the European blue-dye plant whose leaves yield indigo-equivalent indigotin. Used by Pictish warriors as body paint and the dominant pre-industrial European blue dye until East Indian indigo displaced it in the seventeenth century. The color refers to a freshly woad-dyed wool: a saturated, slightly cool deep blue with the matte finish of plant-and-mordant dye.

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.

#37c5d1
Original
#b5bdd2
Protanopia
#a0add2
Deuteranopia
#00cdc8
Tritanopia
#a8a8a8
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
2.09:1
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
10.07:1

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