#21B310

sRGB · 33 / 179 / 16

#21B310 belongs to the green family. Its hex code tells a screen to mix 33 red, 179 green and 16 blue on a scale of 0 to 255. On the HSL wheel, hue is a position around a circle: 113.7° lands in the green region. Its 83.6% saturation makes it strong in color at this lightness. HSL lightness is 38.2% 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 (7.52:1), which helps the shapes of letters stand out.

Color conversions

sRGB (8-bit): 33, 179, 16
HSL: 113.74°, 83.59%, 38.24%
HSV / HSB: 113.74°, 91.06%, 70.20%
CMYK (approx.): 81.56%, 0.00%, 91.06%, 29.80%
CIE XYZ (D65, Y = 100 for white): 16.840, 32.600, 5.895
CIELAB (D65, 2° observer): 63.835, -63.290, 61.991
WCAG relative luminance: 0.32601
24-bit decimal: 2208528

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 #21B310 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 · 7.52:1

Normal text: AAA
Large text: AAA

White text · 2.79:1

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

#A210B3 sits half a turn (180°) from #21B310 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.

#21B310 #A210B3

Analogous

#72B310 and #10B351 sit 30° to either side of #21B310. 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.

#72B310 #21B310 #10B351

Triadic

#21B310, #1021B3 and #B31021 are spaced 120° apart, forming a triangle on the wheel. Try one for the main color and the other two for accents.

#21B310 #1021B3 #B31021

Split complementary

Start at #21B310 and look across the wheel. #5110B3 and #B31072 sit 30° to either side of its exact opposite, giving you two different accent choices.

#21B310 #5110B3 #B31072

Square

Starting with #21B310, each quarter turn (90°) takes you to the next hue: #1072B3, #A210B3, then #B35110. Across the square, #21B310 pairs with #A210B3, and #1072B3 with #B35110.

#21B310 #1072B3 #A210B3 #B35110

Tetradic

#21B310 and #A210B3 are opposites, as are #10B3A2 and #B31021. Together they form a rectangle on the wheel, with alternating gaps of 60° and 120°.

#21B310 #10B3A2 #A210B3 #B31021

Tints

Mixing #21B310 with white in 20% steps produces this scale. The first mixture, #4DC240, keeps 80% of the original. By #D3F0CF, the mixture is 80% white.

#21B310 #4DC240 #7AD170 #A6E19F #D3F0CF #FFFFFF

Shades

Mixing #21B310 with black in 20% steps produces this scale. The first mixture, #1A8F0D, keeps 80% of the original. By #072403, the mixture is 80% black.

#21B310 #1A8F0D #146B0A #0D4806 #072403 #000000

Tones

Mixing #21B310 with middle gray in 20% steps produces this scale. The first mixture, #34A926, keeps 80% of the original. By #6D8A6A, the mixture is 80% middle gray.

#21B310 #34A926 #479F3D #5A9453 #6D8A6A #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

#21B310

RGB

rgb(33 179 16)

HSL

hsl(113.742 83.590% 38.235%)

CSS example

.color-sample {
  background-color: #21B310;
  color: #000000;
}

Channel breakdown

RGB

#21B310 uses 33 red, 179 green and 16 blue. Each bar shows how much of that channel’s 0–255 range the screen uses.

Red 12.9%

Green 70.2%

Blue 6.3%

CMYK

A simple CMYK estimate for #21B310 is 81.6% cyan, 0.0% magenta, 91.1% yellow and 29.8% black. These are ink amounts; a printer profile is needed to predict the result on paper.

Cyan 81.6%

Magenta 0.0%

Yellow 91.1%

Black 29.8%

Nearby colors

The nearest shorthand match is #22BB11. Its matching digit pairs let you write it as #2B1 in CSS. For a modern design, keep #21B310 when you want an exact match. Use its web-safe neighbor, #33CC00, when matching a legacy palette of 216 colors.

Nearest shorthand · #22BB11 Nearest web-safe · #33CC00

Gradient to complement

#21B310 #37982B #4C7D46 #626262 #77467D #8D2B98 #A210B3

Color vision previews

Compare how #21B310 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.

#B7A100

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.

#A8972B

Tritanopia

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

#00AD98

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.

#98A600

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.

#91A124

Tritanomaly (50%)

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

#2EB060

Grayscale (luminance)

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

#9B9B9B

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.

#73A771

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 0.01521 G 0.45079 B 0.00518

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 0.33634 G 0.69175 B 0.21393

Linear Display P3

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

R 0.09254 G 0.43633 B 0.03761

CIE xyY

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

x 0.304 y 0.589 Y 32.600

CMY

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

C % 87.059 M % 29.804 Y % 93.725

Binary RGB

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

00100001 10110011 00010000