#40BF21

sRGB · 64 / 191 / 33

#40BF21 belongs to the green family. Its hex code tells a screen to mix 64 red, 191 green and 33 blue on a scale of 0 to 255. On the HSL wheel, hue is a position around a circle: 108.2° lands in the green region. Its 70.5% saturation makes it strong in color at this lightness. HSL lightness is 43.9% on a scale from black (0%) to white (100%). Of black and white lettering, black has the clearer light-to-dark separation on this background (8.69:1), which helps the shapes of letters stand out.

Color conversions

sRGB (8-bit): 64, 191, 33
HSL: 108.23°, 70.54%, 43.92%
HSV / HSB: 108.23°, 82.72%, 74.90%
CMYK (approx.): 66.49%, 0.00%, 82.72%, 25.10%
CIE XYZ (D65, Y = 100 for white): 21.019, 38.460, 7.755
CIELAB (D65, 2° observer): 68.358, -61.250, 62.549
WCAG relative luminance: 0.38461
24-bit decimal: 4243233

CMYK uses a profile-free approximation. Printed output depends on the press, ink and paper. Lab uses a D65 white point.

Text contrast

Contrast tells you how clearly lettering separates from #40BF21 in light and dark. The ratio compares relative luminance, a measure of light weighted for human vision. Identical colors give 1:1 and black against white gives 21:1. A ratio of 2.99:1 falls just below the 3:1 AA minimum for large text. Body text needs at least 4.5:1 because its finer strokes are harder to distinguish.

Black text · 8.69:1

Normal text: AAA
Large text: AAA

White text · 2.42:1

Normal text: Fail
Large text: Fail

AA and AAA are WCAG accessibility levels. AAA sets a higher bar: 7:1 for normal text and 4.5:1 for large text. Large text begins at 18 pt regular or 14 pt bold. Ratings use the unrounded ratio. WCAG text contrast guidance

Palettes & scales

Harmonies rotate the hue. Scales mix the starting color with white, black or middle gray in 20% steps in encoded sRGB.

Complementary

#A021BF sits half a turn (180°) from #40BF21 on the HSL wheel. Keeping saturation and lightness steady while crossing to the opposite hue gives you a contrasting accent. Check text contrast separately before using the pair for lettering.

#40BF21 #A021BF

Analogous

#8FBF21 and #21BF51 sit 30° to either side of #40BF21. The three hues are neighbors on the wheel, so you can change the color of a border or highlight while keeping it close to the original.

#8FBF21 #40BF21 #21BF51

Triadic

#40BF21, #2140BF and #BF2140 are spaced 120° apart, forming a triangle on the wheel. Try one for the main color and the other two for accents.

#40BF21 #2140BF #BF2140

Split complementary

Start at #40BF21 and look across the wheel. #5121BF and #BF218F sit 30° to either side of its exact opposite, giving you two different accent choices.

#40BF21 #5121BF #BF218F

Square

Starting with #40BF21, each quarter turn (90°) takes you to the next hue: #218FBF, #A021BF, then #BF5121. Across the square, #40BF21 pairs with #A021BF, and #218FBF with #BF5121.

#40BF21 #218FBF #A021BF #BF5121

Tetradic

#40BF21 and #A021BF are opposites, as are #21BFA0 and #BF2140. Together they form a rectangle on the wheel, with alternating gaps of 60° and 120°.

#40BF21 #21BFA0 #A021BF #BF2140

Tints

Mixing #40BF21 with white in 20% steps produces this scale. The first mixture, #66CC4D, keeps 80% of the original. By #D9F2D3, the mixture is 80% white.

#40BF21 #66CC4D #8CD97A #B3E5A6 #D9F2D3 #FFFFFF

Shades

Mixing #40BF21 with black in 20% steps produces this scale. The first mixture, #33991A, keeps 80% of the original. By #0D2607, the mixture is 80% black.

#40BF21 #33991A #267314 #1A4C0D #0D2607 #000000

Tones

Mixing #40BF21 with middle gray in 20% steps produces this scale. The first mixture, #4DB234, keeps 80% of the original. By #738D6D, the mixture is 80% middle gray.

#40BF21 #4DB234 #5AA647 #66995A #738D6D #808080

Copy color codes

Hex, RGB and HSL are three ways to write this screen color. Paste any of them into a CSS color property.

Hex

#40BF21

RGB

rgb(64 191 33)

HSL

hsl(108.228 70.536% 43.922%)

CSS example

.color-sample {
  background-color: #40BF21;
  color: #000000;
}

Channel breakdown

RGB

#40BF21 uses 64 red, 191 green and 33 blue. Each bar shows how much of that channel’s 0–255 range the screen uses.

Red 25.1%

Green 74.9%

Blue 12.9%

CMYK

A simple CMYK estimate for #40BF21 is 66.5% cyan, 0.0% magenta, 82.7% yellow and 25.1% black. These are ink amounts; a printer profile is needed to predict the result on paper.

Cyan 66.5%

Magenta 0.0%

Yellow 82.7%

Black 25.1%

Nearby colors

The nearest shorthand match is #44BB22. Its matching digit pairs let you write it as #4B2 in CSS. For a modern design, keep #40BF21 when you want an exact match. Use its web-safe neighbor, #33CC33, when matching a legacy palette of 216 colors.

Nearest shorthand · #44BB22 Nearest web-safe · #33CC33

Gradient to complement

#40BF21 #50A53B #608A56 #707070 #80568A #903BA5 #A021BF

Color vision previews

Compare how #40BF21 appears in each simulation. When two chart lines or status indicators become hard to tell apart, a label, shape or line pattern gives readers another way to distinguish them. Individual perception varies.

Protanopia

A red–green color vision deficiency. Without a distinct response from long-wavelength cones, some reds and greens can look alike, and reds can appear darker.

#C4AD00

Deuteranopia

A red–green color vision deficiency. Without a distinct response from medium-wavelength cones, some greens can be difficult to distinguish from reds or browns.

#B5A336

Tritanopia

A blue–yellow color vision deficiency. Without a distinct response from short-wavelength cones, blue can resemble green, and yellow can resemble pink.

#28B9A3

Protanomaly (50%)

An altered long-wavelength cone response can make reds appear dimmer and harder to distinguish from greens. This swatch shows the model’s halfway setting.

#A5B213

Deuteranomaly (50%)

An altered medium-wavelength cone response can reduce the visible difference between reds and greens. This swatch shows the model’s halfway setting.

#9EAD2F

Tritanomaly (50%)

An altered short-wavelength cone response can make blue harder to distinguish from green. This swatch shows the model’s halfway setting.

#48BB69

Grayscale (luminance)

This design check removes hue and preserves relative luminance so you can compare light and dark areas.

#A7A7A7

Partial grayscale (50% blend)

This design check mixes the original color halfway toward its grayscale equivalent in linear light. Use it to see how a design holds up as color fades.

#81B37C

Technical reference

CAM16 and CIECAM02 below assume D65 white, an average surround, background Y of 20 against white at 100, and adapting luminance of 4.07 cd/m².

Linear sRGB

These channels scale with emitted light. Use them for lighting calculations and physically meaningful blends.

R 0.05127 G 0.52100 B 0.01521

Display P3

P3 displays can reproduce a wider range of reds and greens. These coordinates reproduce this same sRGB swatch on a color-managed P3 display.

R 0.40255 G 0.73890 B 0.25388

Linear Display P3

These P3 channels are proportional to light, before display encoding.

R 0.13466 G 0.50540 B 0.05244

CIE xyY

The x and y coordinates locate chromaticity on a diagram. Y gives relative luminance on a scale where white is 100.

x 0.313 y 0.572 Y 38.460

CMY

Ideal cyan, magenta and yellow are the complements of the encoded red, green and blue channels.

C % 74.902 M % 25.098 Y % 87.059

Binary RGB

Each eight-bit group represents one channel. Together they store the 24-bit hex color.

01000000 10111111 00100001