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Trustworthy Cataract

#155b5d
Notes

Trustworthy Cataract (#155B5D) 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 (182°, 63%, 22%) 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 red. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#155b5d
RGB
rgb(21, 91, 93)
HSL
hsl(182, 63%, 22%)
HWB
hwb(182 8% 64%)
OKLCH
oklch(43.1% 0.066 197.9)
P3
color(display-p3 0.1709 0.3515 0.3613)
HSV
hsv(182, 77%, 36%)
LAB
lab(34.87% -19.88 -7.29)
LCH
lch(34.87% 21.17 200.13)
CMYK
cmyk(77%, 2%, 0%, 64%)

Etymology

Trustworthy
adjective

Old English trēow, trust — adjectival suffix -worthy. As a color modifier, trustworthy implies a clear-and-reliable-and-honest quality where the hue carries the visual register of confidence-deserving-and-faithful-performance design-element. Sits at the crisp-and-honest end of the grid, parallel to reliable and dependable in usage.

Cataract
noun

A large waterfall with significant volume — particularly the Cataracts of the Nile and the Iguaçu Cataract of South America. Cataract color refers to the deep blue-white of high-volume falling water at Iguaçu: a saturated, slightly cool deep blue-white with the optical brightness of micron-scale air-water mixing.

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.

#155b5d
Original
#54565d
Protanopia
#4a4f5d
Deuteranopia
#005e5b
Tritanopia
#4c4c4c
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
7.82:1
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
2.69:1

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
##155B5D
Display P3
Display P3
color(display-p3 0.1709 0.3515 0.3613)
Inside sRGBOKLCH chroma 0.066

This color sits well within the sRGB cube. P3 and sRGB share the gray axis and most desaturated tones, so a P3 display renders this identically to an sRGB display.

Related Colors

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