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Effective Roman Topaz

#01c4ba
Notes

Effective Roman Topaz (#01C4BA) 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 (177°, 99%, 39%) 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
#01c4ba
RGB
rgb(1, 196, 186)
HSL
hsl(177, 99%, 39%)
HWB
hwb(177 0% 23%)
OKLCH
oklch(73.9% 0.128 188.3)
HSV
hsv(177, 99%, 77%)
LAB
lab(71.57% -42.38 -6.58)
LCH
lch(71.57% 42.88 188.82)
CMYK
cmyk(99%, 0%, 5%, 23%)

Etymology

Effective
adjective

Latin effectīvus, productive — adjectival suffix -ive. As a color modifier, effective implies a clear-and-purpose-achieving quality where the hue carries the visual register of successful-task-completion design-element. Sits at the crisp-and-functional end of the grid, parallel to practical and useful in usage.

Roman
modifier

Latin Romanus, of-Rome. As a color modifier, roman implies an empire-built-and-classical quality, the visual register of Roman-Imperial hand-laid pavement-and-fresco-and-bronze-and-marble Republican-Imperial classical surfaces under Mediterranean-Roman-Imperial classical-architecture afternoon light. Sits at the modifier-and-cultural end of the grid, parallel to etruscan and hellenic in usage.

Topaz
noun

A fluorine aluminum silicate gem, hardness 8 on the Mohs scale, mined for centuries in Ouro Preto, Brazil. Imperial topaz is the prized variety: a warm, slightly pink-shifted gold-orange with the high refractive index of a quality cut stone. Cooler than amber, brighter than honey, with the gem's signature internal fire when held to light. Named for the island of Topazos in the Red Sea, though that source produced peridot instead.

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.

#01c4ba
Original
#b8b9ba
Protanopia
#a2a9bb
Deuteranopia
#00c9c1
Tritanopia
#9a9a9a
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
2.19:1
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
9.61:1

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