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yellow · warm

#b5d511

a balanced, electric yellow · warm · closest name: Yellow Green

Token name suggestion: Studio Straw

RGB
181, 213, 17
HSL
70°, 85%, 45%
CMYK
15, 0, 92, 17
Luminance
0.5745

#b5d511 is a balanced electric yellow, 70° on the wheel and 33/100 on the cool side. Put black text on it (12.49:1). As text it scores 1.68:1 on white — use #697B0A instead. Nearest name is Yellow Green, nearest Tailwind family is lime.

hsl(70 85% 45%)rgb(181 213 17)Base step 600AAA inkWarm

At a glance

Every number on this page in one read: what #b5d511 is made of, how bright it looks, and which way it leans.

Hex
#b5d511
Hue
70°
yellow
Saturation
85%
electric
Lightness
45%
balanced
Brightness
84%
HSV value
Perceived
75%
weighted brightness
Luminance
0.5745
WCAG relative
Temperature
Warm
33/100 cool
Color family
Yellow
Tone
Electric
Best ink
Black
12.49:1
Closest name
Yellow Green
ΔE2000 5.7
Chroma
84.3
LCH, 0–130ish
OKLCH L
0.821
perceptual lightness
Tailwind
lime
500 · ΔE 7.9
Web-safe
#CCCC00
nearest of 216
Where it sits
Hue70° of 360°
Saturation85%
Lightness45%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #b5d511.

Temperature
Warm ← → Cool33% cool

Reads warm. Warm and cool siblings keep the same lightness, so you can swap one in without redoing your contrast maths.

Luminance by channel
Red17%
Green83%
Blue0%

Green carries most of what the eye calls brightness — that is why WCAG weights it 0.7152.

Every format

HEX#b5d511
HEX (8-digit)#b5d511ff
RGBrgb(181, 213, 17)
RGBArgba(181, 213, 17, 1)
HSLhsl(70, 85%, 45%)
HSV / HSBhsv(70, 92%, 84%)
HWBhwb(70 7% 16%)
CMYKcmyk(15%, 0%, 92%, 17%)
LABlab(80.4 -32.0 78.0)
LCHlch(80.4 84.3 112.3)
OKLCHoklch(0.821 0.192 120.1)
XYZ (D65)xyz(42.95, 57.45, 9.36)
Decimal11916561
Display P3color(display-p3 0.710 0.835 0.067)
Web-safe#CCCC00

Copy-ready code

every platformclick to select
/* CSS */
color: #b5d511;
background-color: #b5d511;
/* CSS custom property */
--brand: #b5d511;
/* Tailwind (arbitrary) */
class="text-[#b5d511] bg-[#b5d511]"
/* SCSS */
$brand: #b5d511;
/* SwiftUI */
Color(red: 0.710, green: 0.835, blue: 0.067)
/* UIKit */
UIColor(red: 0.710, green: 0.835, blue: 0.067, alpha: 1)
/* Android XML */
<color name="brand">#B5D511</color>
/* Android Compose */
Color(0xFFB5D511)
/* Flutter */
Color(0xFFB5D511)
/* Python / OpenCV (BGR) */
(17, 213, 181)
/* Python / PIL (RGB) */
(181, 213, 17)
/* Java AWT */
new Color(181, 213, 17)
/* .NET */
Color.FromArgb(255, 181, 213, 17)
/* OpenGL / Unity (0–1) */
(0.7098f, 0.8353f, 0.0667f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{181,213,17}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #b5d511 85%, white);
border-color: color-mix(in oklab, #b5d511 40%, transparent);
/* theme-aware in one line */
color: light-dark(#647609, #EAEED3);
/* relative colour syntax */
--hover: hsl(from #b5d511 h s calc(l - 7));

Design tokens

The same ramp in the four formats a team actually needs. Paste one and the whole palette lands with it.

css custom propertiesclick to select
:root {
  --brand-50: #FBFCF2;
  --brand-100: #F7FAE5;
  --brand-200: #EFF7C5;
  --brand-300: #E7F797;
  --brand-400: #DBF363;
  --brand-500: #CFEE2F;
  --brand-600: #b5d511;
  --brand-700: #A1BD0F;
  --brand-800: #80970C;
  --brand-900: #5E6D0D;
  --brand-950: #3A4408;
  --brand: #b5d511;
  --brand-ink: #000000;
  --brand-surface: #F9FAF4;
  --brand-border: #E5EDC0;
  --brand-hover: #99B40E;
  --brand-pressed: #7D930C;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #222414;
    --brand-ink: #EAEED3;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#FBFCF2',
        100: '#F7FAE5',
        200: '#EFF7C5',
        300: '#E7F797',
        400: '#DBF363',
        500: '#CFEE2F',
        600: '#b5d511',
        700: '#A1BD0F',
        800: '#80970C',
        900: '#5E6D0D',
        950: '#3A4408',
        DEFAULT: '#b5d511',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #FBFCF2,
  '100': #F7FAE5,
  '200': #EFF7C5,
  '300': #E7F797,
  '400': #DBF363,
  '500': #CFEE2F,
  '600': #b5d511,
  '700': #A1BD0F,
  '800': #80970C,
  '900': #5E6D0D,
  '950': #3A4408,
);
$brand-base: #b5d511;
$brand-ink: #000000;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#FBFCF2", "$type": "color" },
      "100": { "$value": "#F7FAE5", "$type": "color" },
      "200": { "$value": "#EFF7C5", "$type": "color" },
      "300": { "$value": "#E7F797", "$type": "color" },
      "400": { "$value": "#DBF363", "$type": "color" },
      "500": { "$value": "#CFEE2F", "$type": "color" },
      "600": { "$value": "#b5d511", "$type": "color" },
      "700": { "$value": "#A1BD0F", "$type": "color" },
      "800": { "$value": "#80970C", "$type": "color" },
      "900": { "$value": "#5E6D0D", "$type": "color" },
      "950": { "$value": "#3A4408", "$type": "color" }
    },
    "brandInk": { "$value": "#000000", "$type": "color" }
  }
}

Best text color

Only one of black and white can be right. This is the one, with the number that proves it.

Readable at a glance#000000 on #b5d511 · 12.49:1
Use #000000AAA at every size.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 1.68:1
AA fail · AA large fail · AAA fail
Aa
Black text · 12.49:1 · recommended
AA pass · AA large pass · AAA pass
Reading the other direction: #b5d511 as text scores 1.68:1 on white and 12.49:1 on black.
Best tinted ink on it, if plain black or white feels flat: #647609 at 3.02:1.

Make it accessible

A contrast checker tells you that you failed. This tells you what to ship instead — same hue, same saturation, lightness moved only as far as WCAG demands.

The quick fox
#697B0A · 4.73:1
AA on white−19% L
#697B0A
The quick fox
#515F08 · 7.02:1
AAA on white−25% L
#515F08
The quick fox
#b5d511 · 12.49:1
AA on blackalready passes
#b5d511
The quick fox
#b5d511 · 12.49:1
AAA on blackalready passes
#b5d511

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #859C0C is enough for headings on white. Non-text elements such as icons, chart strokes and focus rings also sit at 3:1 under WCAG 2.2 (1.4.11).

Accessibility — WCAG contrast

Aa
#b5d511 on white: 1.68:1
AA ✗ fail · AA-large · AAA
Aa
#b5d511 on black: 12.49:1
AA ✓ pass · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #b5d511 as text on that neutral, and that neutral as text on #b5d511.

NeutralRatioBoth directions
White1.68:1AaAa
Slate 501.61:1AaAa
Slate 1001.53:1AaAa
Slate 2001.36:1AaAa
Slate 3001.13:1AaAa
Slate 4001.53:1AaAa
Slate 5002.83:1AaAa
Slate 6004.51:1AaAa
Slate 7006.16:1AaAa
Slate 8008.70:1AaAa
Slate 90010.62:1AaAa
Black12.49:1AaAa
Colour vision deficiency
true color
protanopia · #E3C800
deuteranopia · #DFC82F
tritanopia · #C0C9B5

Roughly one man in twelve has some form of colour vision deficiency. If any of the three panels above is hard to tell apart from a neighbouring colour in your palette, add a shape, an icon or a label so the meaning does not rest on hue alone.

Color scale — 50 to 950

A Tailwind-shaped ramp built around this exact hex. #b5d511 is pinned to step 600; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#FBFCF2
#F7FAE5
#EFF7C5
#E7F797
#DBF363
#CFEE2F
#b5d511
#A1BD0F
#80970C
#5E6D0D
#3A4408
Base = 600Lightest = 50 · #FBFCF2Darkest = 950 · #3A4408Text step on white = 900
Perceptual ramp — OKLCH

The same eleven steps expressed in OKLCH, where equal lightness numbers actually look equally spaced. HSL ramps go muddy in the yellows and washed out in the blues; this one does not. Modern browsers render it natively — the hex ramp above is the fallback.

50100200300400500600700800900950
oklch tokensclick to select
:root {
  --brand-50: oklch(0.97 0.048 120.1);
  --brand-100: oklch(0.94 0.077 120.1);
  --brand-200: oklch(0.88 0.115 120.1);
  --brand-300: oklch(0.80 0.150 120.1);
  --brand-400: oklch(0.72 0.177 120.1);
  --brand-500: oklch(0.64 0.192 120.1);
  --brand-600: oklch(0.56 0.192 120.1);
  --brand-700: oklch(0.48 0.181 120.1);
  --brand-800: oklch(0.40 0.162 120.1);
  --brand-900: oklch(0.32 0.135 120.1);
  --brand-950: oklch(0.24 0.106 120.1);
}

Colors that work with #b5d511

Not a palette — a role sheet. Each swatch answers one question you will hit while building the component.

Text on it#000000
Black wins here
Surface#F9FAF4
Tinted page background
Border#E5EDC0
Hairlines and dividers
Muted text#8E9B4B
Captions on the surface
Accent#0C1EDA
Second voice, not a rival
Dark variant#647609
Hover, pressed, headers
Light variant#FAFDE7
Selected rows, tints
Dark surface#222414
Dark-mode background
Hover#99B40E
One step down in lightness
Pressed#7D930C
Two steps down
Disabled#B8BE99
Chroma pulled out
Focus ring#CDF406
Offset from the fill so it reads
Light mode
Everything in its place

Surface, border, heading and body all derive from this one hue, so the screen stays coherent without a second palette.

Primary actionSecondaryBadge
Dark mode
Same hue, inverted

Lightness flips, hue holds. The accent stays the anchor in both themes.

Primary actionSecondaryAccent

In real components

The same eight roles, wired into the interface patterns you will actually build with them. Every state below is a computed value, not a mock-up.

Buttons and states
Save changesHoverPressedDisabled
OutlineSubtleLinkFocused
Form field
you@company.com

Focus ring uses the light variant so the field still reads as one shape.

Send me product updates
Notice
Your export is ready

The file stays available for seven days. Download it before it expires.

NewBetaDraft
Data
Storage used68%
Acme LtdActive
NorthwindTrial
GlobexActive

How to use #b5d511

Derived from its contrast, chroma and lightness — not from taste.

Works well for
  • Text and icons on dark surfaces
  • Primary buttons and calls to action
  • Focus rings, active and selected states
  • Brand accents, badges and data highlights
  • Chart series and data categories
Use with care
  • Text of any size on white — fails WCAG AA
  • Full-page backgrounds — tiring over long sessions
  • Thin strokes and 1px borders — they disappear on light UI
  • Pairing with a same-lightness hue — edges vibrate
Minimum size as text on white
Not as text
Safe as a fill behind white type
No — use #647609
Safe as a 1px border on white
No — use #859C0C

Meaning and mood

What a colour in this family tends to signal, and how this particular chroma and lightness change the reading.

optimisticalertcheap-and-cheerfulvisible

The most visible hue at low light levels, which is why it owns warnings, hazard tape and value retail.

At this chroma the association is amplified — it will dominate anything placed beside it, so give it space and use it sparingly. The mid lightness keeps it versatile in both themes.

Worth knowing

Almost never passes contrast against white. Treat it as a surface or a marker, not as text.

Reads as
  • FormalityLow
  • EnergyHigh
  • Weight55/100
  • TemperatureWarm
  • ApproachabilityHigh

Colour associations are cultural and vary by market. Treat these as a starting point for a conversation with your audience, not a finding about them.

Similar colors

One move away from this hex in each direction. Every swatch is its own page.

Color relationships

The wheel positions with their names attached, so you can grab the one you actually need.

Complementary#3111D5
Analogous left#D59311
Analogous right#53D511
Split-complement 1#1153D5
Split-complement 2#9311D5
Triadic 1#11B5D5
Triadic 2#D511B5
Tetradic#11D593
On the wheel
Base+30°−30°+120°+240°+180°70°

#b5d511 sits at 70°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red71.0%
Green83.5%
Blue6.7%
R · 0–255
181
0xb5
G · 0–255
213
0xd5
B · 0–255
17
0x11

CMYK percentages

Cyan15.0%
Magenta0.0%
Yellow92.0%
Key (black)16.5%

Total ink coverage is 124%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#b5d511 text on a black background

contrast 12.49:1

Card sample

#b5d511 text on a white background

contrast 1.68:1

Card sample

#b5d511 on grey

1.53:1

#b5d511 on its own surface

1.60:1

#b5d511 on its dark surface

9.39:1

CSS3 live lab

Text font color

The quick brown fox

color: #b5d511;
Background color
Panel with #b5d511 background
background-color: #b5d511;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #b5d511;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(181, 213, 17, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(181, 213, 17, 0.45);
Border & gradient
Gradient panel
border: 3px solid #b5d511;
background: linear-gradient(135deg, #b5d511, #32D511);
Gradient text

Gradient headline

background: linear-gradient(90deg, #b5d511, #11D521);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #b5d511;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #b5d511;
caret-color: #b5d511;
Left rule
Pull quote or callout
border-left: 4px solid #b5d511;
Ring + tint
Selected chip
background: #FAFDE7;
box-shadow: inset 0 0 0 2px #b5d511;
Conic badge
68%
background: conic-gradient(#b5d511 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #b5d511 over white; the bottom row is the same alpha over a checkerboard, so you can see what survives on a photo or a video.

Bottom row of hexes is the flattened result over white — use those when a design tool refuses transparency, or when you need a solid fallback.

alpha in every syntaxclick to select
rgba(181, 213, 17, 0.5)
rgb(181 213 17 / 50%)
#b5d51180
hsl(70 85% 45% / 50%)
color-mix(in srgb, #b5d511 50%, transparent)
Alpha8-digit hexFlat on white
10%#b5d5111a#F8FBE7
20%#b5d51133#F0F7CF
40%#b5d51166#E1EEA0
60%#b5d51199#D3E670
80%#b5d511cc#C4DD41

Gradients from #b5d511

Six recipes, each built from this hex and shown with the exact CSS that produced it.

Elevation
Same hue, three lightnesses — safe anywhere
background: linear-gradient(135deg, #D0EF34, #b5d511 45%, #647609);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #b5d511, #1DB90F);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #b5d511, #3111D5);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #D7F151 0%, #b5d511 45%, #647609 100%);
Soft wash
Section backgrounds that stay readable
background: linear-gradient(180deg, #F9FAF4, #ffffff);
Mesh
Ambient background, no image weight
background: radial-gradient(60% 60% at 15% 20%, #EE9C2B 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #4EED18 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #647609 0%, transparent 65%), #b5d511;

Monochromatic scale

Palettes built from #b5d511

Shades — darker

Tints — lighter

Tones — desaturated

Color harmonies

Nearest named colors

Ranked with CIEDE2000 across all 139 CSS keywords. Under ΔE 2 the eye stops telling them apart; over ΔE 10 they are plainly different colors.

#b5d511 in the real world

Where a color in this family tends to land, and the interface roles it is usually asked to play.

Industries
RetailLeisureEnergyWarning systems
Common UI roles
ButtonsLinksFocus statesCharts
Print note

Sits outside most CMYK gamuts — expect a duller press result, or specify a spot ink.

On screens

Holds up across typical panel gamma. Still worth checking on an uncalibrated laptop, where mid-tones shift most.

In dark mode

Usable as-is on a dark surface at 12.49:1.

Explore nearby colors

Small, deliberate steps away from this hex — useful when you are hunting for the version of a colour that finally feels right.

#b5d511, answered

What color is #b5d511?

#b5d511 is a balanced electric yellow, closest to Yellow Green (ΔE2000 5.7). It sits at 70° on the hue wheel with 85% saturation and 45% lightness, which reads as warm.

What is the RGB value of #b5d511?

rgb(181, 213, 17) — 181 red, 213 green and 17 blue out of 255, or 71% / 83.5% / 6.7% by channel.

What is #b5d511 in HSL and HSV?

hsl(70, 85%, 45%) and hsv(70, 92%, 84%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #b5d511 a light or a dark color?

It is a light color. Relative luminance is 0.5745 and perceived brightness is 75%, so black text on it reaches 12.49:1.

Should I use black or white text on #b5d511?

Black. It scores 12.49:1 against #b5d511, versus 1.68:1 for white — AAA at any size.

Is #b5d511 accessible on a white background?

#b5d511 on white scores 1.68:1, which fails WCAG AA at every size. Darken it to #697B0A to reach 4.5:1, or #515F08 for 7:1.

What is the complementary color of #b5d511?

#3111D5 sits directly opposite on the wheel. Softer options are the split-complements #1153D5 and #9311D5, which give the same contrast with far less vibration.

What colors go well with #b5d511?

For interface work: #F9FAF4 as the surface, #E5EDC0 for borders, #8E9B4B for secondary text, #0C1EDA as an accent and #647609 for hover and pressed states. For a palette, the analogous pair #D59311 and #53D511 stays calm, while #3111D5 is the loudest partner.

What is #b5d511 in CMYK for printing?

cmyk(15%, 0%, 92%, 17%). This is a screen-to-ink approximation — a color this saturated sits outside most CMYK gamuts and will print duller than it looks here.

Is #b5d511 warm or cool?

Warm — it scores 33 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #D5AD11; nudged cooler, #6DD70F.

Which Tailwind color is closest to #b5d511?

The lime family — its 500 step is #84cc16, ΔE2000 7.9 away. That is a visible difference, so define #b5d511 as a custom token rather than reaching for the built-in.

How do I use #b5d511 in Tailwind CSS?

Inline it as an arbitrary value with bg-[#b5d511] or text-[#b5d511], or register the whole ramp under theme.extend.colors.brand so you get bg-brand-500 and friends. The generated 50–950 scale on this page is ready to paste into your config.

What is #b5d511 with 50% opacity?

rgba(181, 213, 17, 0.5), or #b5d51180 in eight-digit hex. Over white that composites to #DAEA88; over black, #5B6B09.

Is #b5d511 a web-safe color?

No. The nearest web-safe colour is #CCCC00, ΔE2000 6.7 away. The palette only matters for legacy displays and some email clients now.

What does the color #b5d511 mean?

As a yellow, it reads optimistic, alert, cheap-and-cheerful. The most visible hue at low light levels, which is why it owns warnings, hazard tape and value retail. At this chroma the effect is amplified — it will dominate whatever sits beside it.

What gradient works with #b5d511?

The safest is same-hue elevation: linear-gradient(135deg, #D0EF34, #b5d511 45%, #647609). For more colour, a short hue run to #1DB90F keeps it rich without turning muddy.

Work with #b5d511 in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #b5d511 at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.