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Effective Sour Verdigris

#42aa9f
Notes

Effective Sour Verdigris (#42AA9F) is a true teal with an earthy character. It leans grounded and natural, the kind of color that plays well with wood, clay, linen, and warm neutrals. Its HSL profile (174°, 44%, 46%) 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
#42aa9f
RGB
rgb(66, 170, 159)
HSL
hsl(174, 44%, 46%)
HWB
hwb(174 26% 33%)
OKLCH
oklch(67.5% 0.097 185.5)
P3
color(display-p3 0.3752 0.6580 0.6227)
HSV
hsv(174, 61%, 67%)
LAB
lab(63.68% -32.42 -3.24)
LCH
lch(63.68% 32.59 185.71)
CMYK
cmyk(61%, 0%, 6%, 33%)

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.

Sour
modifier

Old English sūr, acid-or-fermented. As a color modifier, sour implies a fermented-and-puckered-and-acid quality, the visual register of sourdough-and-Bavarian-sauerkraut-sour hand-fermented-and-puckered-and-acid sourdough-and-Bavarian-sauerkraut-sour-and-Belgian-Lambic sour-and-fermented-and-puckered surfaces under sourdough-and-Bavarian-sauerkraut-sour-and-Belgian-Lambic San-Francisco-sourdough-and-Brussels-Lambic fermented-puckered-light. Sits at the modifier-and-flavor end of the grid, parallel to tart and tang in usage.

Verdigris
noun

The basic copper carbonate that forms on weathered copper and bronze — the pigment scraped from oxidized metal and used in Renaissance painting before being supplanted by more stable greens. The color refers to a thick verdigris on aged copper roofing or the Statue of Liberty's surface: a soft, slightly muted blue-green with the powdery finish of mineral oxide. Cooler than patina, warmer than seafoam, with the archaeological weight of a mineral made by time.

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.

#42aa9f
Original
#a2a19f
Protanopia
#9295a0
Deuteranopia
#00aea6
Tritanopia
#939393
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
2.81:1
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
7.48:1

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
##42AA9F
Display P3
Display P3
color(display-p3 0.3752 0.6580 0.6227)
P3 has subtle headroomOKLCH chroma 0.097

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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