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Effective Bothnia

#40cabf
Notes

Effective Bothnia (#40CABF) 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 (175°, 57%, 52%) 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
#40cabf
RGB
rgb(64, 202, 191)
HSL
hsl(175, 57%, 52%)
HWB
hwb(175 25% 21%)
OKLCH
oklch(76.4% 0.117 187.3)
HSV
hsv(175, 68%, 79%)
LAB
lab(74.25% -38.87 -5.26)
LCH
lch(74.25% 39.23 187.71)
CMYK
cmyk(68%, 0%, 5%, 21%)

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.

Bothnia
noun

The Gulf of Bothnia — the northernmost arm of the Baltic Sea between Sweden and Finland. Bothnia color refers to mid-depth Gulf of Bothnia water at midsummer: a saturated, slightly cool deep blue with the optical complexity of low-salinity high-latitude brackish water.

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

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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.

#40cabf
Original
#bfbfbf
Protanopia
#abb0c0
Deuteranopia
#00cfc6
Tritanopia
#acacac
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
2.02:1
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
10.42:1

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