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Frank Indicolite

#155a7b
Notes

Frank Indicolite (#155A7B) is a deep cyan with a jewel character. It carries the deep, saturated richness of a gemstone. Authoritative and slightly formal, it works well for type and heavy UI elements. Its HSL profile (199°, 71%, 28%) places it in the balanced band at a dark lightness. It works well as a headline, icon, or deep background in an otherwise light layout, pairing cleanly with cream, bone, and warm neutrals. 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
#155a7b
RGB
rgb(21, 90, 123)
HSL
hsl(199, 71%, 28%)
HWB
hwb(199 8% 52%)
OKLCH
oklch(44.3% 0.085 234.8)
P3
color(display-p3 0.1693 0.3477 0.4707)
HSV
hsv(199, 83%, 48%)
LAB
lab(35.79% -8.41 -24.50)
LCH
lch(35.79% 25.90 251.05)
CMYK
cmyk(83%, 27%, 0%, 52%)

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.

Indicolite
noun

A blue variety of tourmaline — colored by trace iron, mined principally in Brazil, Mozambique, and Pakistan. The color refers to a faceted Brazilian indicolite: a saturated, slightly cool deep blue-green with the gem's signature internal warmth. Cooler than aquamarine.

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.

#155a7b
Original
#4a597d
Protanopia
#3c507a
Deuteranopia
#006365
Tritanopia
#4e4e4e
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).
AAAon White
7.55:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
Failon Black
2.78:1

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
##155A7B
Display P3
Display P3
color(display-p3 0.1693 0.3477 0.4707)
P3 has subtle headroomOKLCH chroma 0.085

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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