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Energetic Brook

#42bb5c
Notes

Energetic Brook (#42BB5C) is a true green 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 (133°, 48%, 50%) 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 magenta. For something softer, pull in its analogous neighbors on either side of the wheel.

HEX
#42bb5c
RGB
rgb(66, 187, 92)
HSL
hsl(133, 48%, 50%)
HWB
hwb(133 26% 27%)
OKLCH
oklch(70.3% 0.172 147.5)
HSV
hsv(133, 65%, 73%)
LAB
lab(67.63% -53.71 38.21)
LCH
lch(67.63% 65.92 144.57)
CMYK
cmyk(65%, 0%, 51%, 27%)

Etymology

Energetic
adjective

Greek energētikós, active — derived from energeia (activity). As a color modifier, energetic implies a saturated-and-kinetic-and-active quality where the hue carries visual vibration and movement-suggestion that engages the eye dynamically. Sits at the bright-and-active end of the grid, parallel to dynamic and spirited in usage.

Brook
noun

A small natural stream — smaller than a creek, particularly the spring-fed brooks of New England and northern Britain. Brook color refers to a clear-bottomed mountain brook seen against pebble bed: a soft, slightly cool pale blue-green with the optical clarity of cold spring-fed 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.

#42bb5c
Original
#bdab54
Protanopia
#aea163
Deuteranopia
#1bb7a5
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
2.47:1
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
8.49:1

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