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Vitreous Cascade

#178fab
Notes

Vitreous Cascade (#178FAB) is a true 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 (191°, 76%, 38%) 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
#178fab
RGB
rgb(23, 143, 171)
HSL
hsl(191, 76%, 38%)
HWB
hwb(191 9% 33%)
OKLCH
oklch(60.2% 0.104 219.1)
P3
color(display-p3 0.2620 0.5525 0.6583)
HSV
hsv(191, 87%, 67%)
LAB
lab(54.83% -20.73 -23.46)
LCH
lch(54.83% 31.30 228.54)
CMYK
cmyk(87%, 16%, 0%, 33%)

Etymology

Vitreous
adjective

Latin vitreus, glass-like — derived from vitrum (glass). As a color modifier, vitreous implies a clear-and-glassy quality where the hue carries the optical clarity of polished crown-glass. Sits at the crisp-and-clear end of the grid, parallel to pellucid and crystalline in usage.

Cascade
noun

A waterfall of moderate size — particularly the Cascade Range of waterfalls along the Pacific Northwest's Columbia River Gorge. Cascade color refers to the white-and-blue of falling water at Multnomah Falls: a soft, slightly cool pale blue-white with the optical complexity of mist-and-water in motion.

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.

#178fab
Original
#7e8bac
Protanopia
#6b7dab
Deuteranopia
#009898
Tritanopia
#787878
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).
AA Largeon White
3.78:1
The quick brown foxSample body text at normal size. The wcag minimum for body contrast is 4.5:1 (AA) or 7:1 (AAA).
AAon Black
5.55:1

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
##178FAB
Display P3
Display P3
color(display-p3 0.2620 0.5525 0.6583)
P3 has subtle headroomOKLCH chroma 0.104

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.

Related Colors

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