#51A310

sRGB · 81 / 163 / 16

#51A310 belongs to the yellow-green family. Its hex code tells a screen to mix 81 red, 163 green and 16 blue on a scale of 0 to 255. On the HSL wheel, hue is a position around a circle: 93.5° lands in the yellow-green region. Its 82.1% saturation makes it strong in color at this lightness. HSL lightness is 35.1% 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 (6.60:1), which helps the shapes of letters stand out.

Color conversions

sRGB (8-bit): 81, 163, 16
HSL: 93.47°, 82.12%, 35.10%
HSV / HSB: 93.47°, 90.18%, 63.92%
CMYK (approx.): 50.31%, 0.00%, 90.18%, 36.08%
CIE XYZ (D65, Y = 100 for white): 16.583, 27.980, 5.017
CIELAB (D65, 2° observer): 59.871, -47.636, 59.115
WCAG relative luminance: 0.27981
24-bit decimal: 5350160

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 #51A310 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 · 6.60:1

Normal text: AA
Large text: AAA

White text · 3.18:1

Normal text: Fail
Large text: AA

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

#6210A3 sits half a turn (180°) from #51A310 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.

#51A310 #6210A3

Analogous

#9AA310 and #10A319 sit 30° to either side of #51A310. 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.

#9AA310 #51A310 #10A319

Triadic

#51A310, #1051A3 and #A31051 are spaced 120° apart, forming a triangle on the wheel. Try one for the main color and the other two for accents.

#51A310 #1051A3 #A31051

Split complementary

Start at #51A310 and look across the wheel. #1910A3 and #A3109A sit 30° to either side of its exact opposite, giving you two different accent choices.

#51A310 #1910A3 #A3109A

Square

Starting with #51A310, each quarter turn (90°) takes you to the next hue: #109AA3, #6210A3, then #A31910. Across the square, #51A310 pairs with #6210A3, and #109AA3 with #A31910.

#51A310 #109AA3 #6210A3 #A31910

Tetradic

#51A310 and #6210A3 are opposites, as are #10A362 and #A31051. Together they form a rectangle on the wheel, with alternating gaps of 60° and 120°.

#51A310 #10A362 #6210A3 #A31051

Tints

Mixing #51A310 with white in 20% steps produces this scale. The first mixture, #74B540, keeps 80% of the original. By #DCEDCF, the mixture is 80% white.

#51A310 #74B540 #97C870 #B9DA9F #DCEDCF #FFFFFF

Shades

Mixing #51A310 with black in 20% steps produces this scale. The first mixture, #41820D, keeps 80% of the original. By #102103, the mixture is 80% black.

#51A310 #41820D #31620A #204106 #102103 #000000

Tones

Mixing #51A310 with middle gray in 20% steps produces this scale. The first mixture, #5A9C26, keeps 80% of the original. By #77876A, the mixture is 80% middle gray.

#51A310 #5A9C26 #64953D #6D8E53 #77876A #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

#51A310

RGB

rgb(81 163 16)

HSL

hsl(93.469 82.123% 35.098%)

CSS example

.color-sample {
  background-color: #51A310;
  color: #000000;
}

Channel breakdown

RGB

#51A310 uses 81 red, 163 green and 16 blue. Each bar shows how much of that channel’s 0–255 range the screen uses.

Red 31.8%

Green 63.9%

Blue 6.3%

CMYK

A simple CMYK estimate for #51A310 is 50.3% cyan, 0.0% magenta, 90.2% yellow and 36.1% black. These are ink amounts; a printer profile is needed to predict the result on paper.

Cyan 50.3%

Magenta 0.0%

Yellow 90.2%

Black 36.1%

Nearby colors

The nearest shorthand match is #55AA11. Its matching digit pairs let you write it as #5A1 in CSS. For a modern design, keep #51A310 when you want an exact match. Use its web-safe neighbor, #669900, when matching a legacy palette of 216 colors.

Nearest shorthand · #55AA11 Nearest web-safe · #669900

Gradient to complement

#51A310 #548B29 #577241 #5A5A5A #5C4172 #5F298B #6210A3

Color vision previews

Compare how #51A310 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.

#A99400

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.

#9E8E26

Tritanopia

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

#4D9D8A

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.

#929900

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.

#8D9520

Tritanomaly (50%)

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

#56A057

Grayscale (luminance)

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

#909090

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.

#769A69

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 0.08228 G 0.36625 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 0.39976 G 0.63171 B 0.19850

Linear Display P3

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

R 0.13270 G 0.35683 B 0.03264

CIE xyY

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

x 0.334 y 0.564 Y 27.980

CMY

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

C % 68.235 M % 36.078 Y % 93.725

Binary RGB

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

01010001 10100011 00010000