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green · neutral

#63ca21

a balanced, vivid green · neutral · closest name: Lime Green

Token name suggestion: Studio Jade

RGB
99, 202, 33
HSL
97°, 72%, 46%
CMYK
51, 0, 84, 21
Luminance
0.4500

#63ca21 is a balanced vivid green, 97° on the wheel and 53/100 on the cool side. Put black text on it (10.00:1). As text it scores 2.10:1 on white — use #418416 instead. Nearest name is Lime Green, nearest Tailwind family is lime.

hsl(97 72% 46%)rgb(99 202 33)Base step 600AAA inkNeutral

At a glance

Every number on this page in one read: what #63ca21 is made of, how bright it looks, and which way it leans.

Hex
#63ca21
Hue
97°
green
Saturation
72%
vivid
Lightness
46%
balanced
Brightness
79%
HSV value
Perceived
64%
weighted brightness
Luminance
0.4500
WCAG relative
Temperature
Neutral
53/100 cool
Color family
Green
Tone
Vivid
Best ink
Black
10.00:1
Closest name
Lime Green
ΔE2000 4.3
Chroma
87.6
LCH, 0–130ish
OKLCH L
0.748
perceptual lightness
Tailwind
lime
500 · ΔE 4.3
Web-safe
#66CC33
nearest of 216
Where it sits
Hue97° of 360°
Saturation72%
Lightness46%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #63ca21.

Temperature
Warm ← → Cool53% cool

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

Luminance by channel
Red6%
Green94%
Blue0%

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

Every format

HEX#63ca21
HEX (8-digit)#63ca21ff
RGBrgb(99, 202, 33)
RGBArgba(99, 202, 33, 1)
HSLhsl(97, 72%, 46%)
HSV / HSBhsv(97, 84%, 79%)
HWBhwb(97 13% 21%)
CMYKcmyk(51%, 0%, 84%, 21%)
LABlab(72.9 -56.4 67.0)
LCHlch(72.9 87.6 130.1)
OKLCHoklch(0.748 0.215 136.8)
XYZ (D65)xyz(26.54, 45.00, 8.73)
Decimal6539809
Display P3color(display-p3 0.388 0.792 0.129)
Web-safe#66CC33

Copy-ready code

every platformclick to select
/* CSS */
color: #63ca21;
background-color: #63ca21;
/* CSS custom property */
--brand: #63ca21;
/* Tailwind (arbitrary) */
class="text-[#63ca21] bg-[#63ca21]"
/* SCSS */
$brand: #63ca21;
/* SwiftUI */
Color(red: 0.388, green: 0.792, blue: 0.129)
/* UIKit */
UIColor(red: 0.388, green: 0.792, blue: 0.129, alpha: 1)
/* Android XML */
<color name="brand">#63CA21</color>
/* Android Compose */
Color(0xFF63CA21)
/* Flutter */
Color(0xFF63CA21)
/* Python / OpenCV (BGR) */
(33, 202, 99)
/* Python / PIL (RGB) */
(99, 202, 33)
/* Java AWT */
new Color(99, 202, 33)
/* .NET */
Color.FromArgb(255, 99, 202, 33)
/* OpenGL / Unity (0–1) */
(0.3882f, 0.7922f, 0.1294f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{99,202,33}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #63ca21 85%, white);
border-color: color-mix(in oklab, #63ca21 40%, transparent);
/* theme-aware in one line */
color: light-dark(#366E12, #DDEED3);
/* relative colour syntax */
--hover: hsl(from #63ca21 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: #F6FCF3;
  --brand-100: #EEF8E7;
  --brand-200: #D9F3C9;
  --brand-300: #BEEF9F;
  --brand-400: #9EE76E;
  --brand-500: #7DDF3E;
  --brand-600: #63ca21;
  --brand-700: #56AF1D;
  --brand-800: #458C17;
  --brand-900: #346615;
  --brand-950: #21400D;
  --brand: #63ca21;
  --brand-ink: #000000;
  --brand-surface: #F7FAF4;
  --brand-border: #D1EDC0;
  --brand-hover: #54AB1C;
  --brand-pressed: #458D17;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #1A2414;
    --brand-ink: #DDEED3;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F6FCF3',
        100: '#EEF8E7',
        200: '#D9F3C9',
        300: '#BEEF9F',
        400: '#9EE76E',
        500: '#7DDF3E',
        600: '#63ca21',
        700: '#56AF1D',
        800: '#458C17',
        900: '#346615',
        950: '#21400D',
        DEFAULT: '#63ca21',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F6FCF3,
  '100': #EEF8E7,
  '200': #D9F3C9,
  '300': #BEEF9F,
  '400': #9EE76E,
  '500': #7DDF3E,
  '600': #63ca21,
  '700': #56AF1D,
  '800': #458C17,
  '900': #346615,
  '950': #21400D,
);
$brand-base: #63ca21;
$brand-ink: #000000;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#F6FCF3", "$type": "color" },
      "100": { "$value": "#EEF8E7", "$type": "color" },
      "200": { "$value": "#D9F3C9", "$type": "color" },
      "300": { "$value": "#BEEF9F", "$type": "color" },
      "400": { "$value": "#9EE76E", "$type": "color" },
      "500": { "$value": "#7DDF3E", "$type": "color" },
      "600": { "$value": "#63ca21", "$type": "color" },
      "700": { "$value": "#56AF1D", "$type": "color" },
      "800": { "$value": "#458C17", "$type": "color" },
      "900": { "$value": "#346615", "$type": "color" },
      "950": { "$value": "#21400D", "$type": "color" }
    },
    "brandInk": { "$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 #63ca21 · 10.00:1
Use #000000AAA at every size.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 2.10:1
AA fail · AA large fail · AAA fail
Aa
Black text · 10.00:1 · recommended
AA pass · AA large pass · AAA pass
Reading the other direction: #63ca21 as text scores 2.10:1 on white and 10.00:1 on black.
Best tinted ink on it, if plain black or white feels flat: #366E12 at 2.94:1.

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
#418416 · 4.63:1
AA on white−16% L
#418416
The quick fox
#2F6110 · 7.40:1
AAA on white−24% L
#2F6110
The quick fox
#63ca21 · 10.00:1
AA on blackalready passes
#63ca21
The quick fox
#63ca21 · 10.00:1
AAA on blackalready passes
#63ca21

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #52A71B 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
#63ca21 on white: 2.10:1
AA ✗ fail · AA-large · AAA
Aa
#63ca21 on black: 10.00:1
AA ✓ pass · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #63ca21 as text on that neutral, and that neutral as text on #63ca21.

NeutralRatioBoth directions
White2.10:1AaAa
Slate 502.01:1AaAa
Slate 1001.92:1AaAa
Slate 2001.70:1AaAa
Slate 3001.41:1AaAa
Slate 4001.22:1AaAa
Slate 5002.27:1AaAa
Slate 6003.61:1AaAa
Slate 7004.93:1AaAa
Slate 8006.97:1AaAa
Slate 9008.50:1AaAa
Black10.00:1AaAa
Colour vision deficiency
true color
protanopia · #D1B800
deuteranopia · #C4B037
tritanopia · #5DC2AC

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. #63ca21 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.

#F6FCF3
#EEF8E7
#D9F3C9
#BEEF9F
#9EE76E
#7DDF3E
#63ca21
#56AF1D
#458C17
#346615
#21400D
Base = 600Lightest = 50 · #F6FCF3Darkest = 950 · #21400DText 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 0.054 136.8);
  --brand-100: oklch(0.94 0.086 136.8);
  --brand-200: oklch(0.88 0.129 136.8);
  --brand-300: oklch(0.80 0.168 136.8);
  --brand-400: oklch(0.72 0.198 136.8);
  --brand-500: oklch(0.64 0.215 136.8);
  --brand-600: oklch(0.56 0.215 136.8);
  --brand-700: oklch(0.48 0.202 136.8);
  --brand-800: oklch(0.40 0.181 136.8);
  --brand-900: oklch(0.32 0.150 136.8);
  --brand-950: oklch(0.24 0.118 136.8);
}

Colors that work with #63ca21

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#F7FAF4
Tinted page background
Border#D1EDC0
Hairlines and dividers
Muted text#6A9B4B
Captions on the surface
Accent#5D1CCF
Second voice, not a rival
Dark variant#366E12
Hover, pressed, headers
Light variant#F0FBE9
Selected rows, tints
Dark surface#1A2414
Dark-mode background
Hover#54AB1C
One step down in lightness
Pressed#458D17
Two steps down
Disabled#AAC09C
Chroma pulled out
Focus ring#69E818
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 #63ca21

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
  • Status meaning — pair it with an icon or label, never colour alone
  • 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 #366E12
Safe as a 1px border on white
No — use #52A71B

Meaning and mood

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

safegrowingnaturalpermissive

Green means go, well, and grown. It carries finance, sustainability and health with almost no explanation needed.

This is a confident chroma: strong enough to lead a brand, restrained enough to live in an interface all day. The mid lightness keeps it versatile in both themes.

Worth knowing

Red/green pairs are the most common colour-blindness failure — never let the two carry meaning alone.

Reads as
  • FormalityMedium
  • EnergyMedium-high
  • Weight54/100
  • TemperatureNeutral
  • ApproachabilityBalanced

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#8821CA
Analogous left#B7CA21
Analogous right#21CA34
Split-complement 1#3421CA
Split-complement 2#CA21B7
Triadic 1#2163CA
Triadic 2#CA2163
Tetradic#21B7CA
On the wheel
Base+30°−30°+120°+240°+180°97°

#63ca21 sits at 97°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red38.8%
Green79.2%
Blue12.9%
R · 0–255
99
0x63
G · 0–255
202
0xca
B · 0–255
33
0x21

CMYK percentages

Cyan51.0%
Magenta0.0%
Yellow83.7%
Key (black)20.8%

Total ink coverage is 156%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#63ca21 text on a black background

contrast 10.00:1

Card sample

#63ca21 text on a white background

contrast 2.10:1

Card sample

#63ca21 on grey

1.92:1

#63ca21 on its own surface

1.99:1

#63ca21 on its dark surface

7.66:1

CSS3 live lab

Text font color

The quick brown fox

color: #63ca21;
Background color
Panel with #63ca21 background
background-color: #63ca21;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #63ca21;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(99, 202, 33, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(99, 202, 33, 0.45);
Border & gradient
Gradient panel
border: 3px solid #63ca21;
background: linear-gradient(135deg, #63ca21, #21CA50);
Gradient text

Gradient headline

background: linear-gradient(90deg, #63ca21, #21CA7A);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #63ca21;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #63ca21;
caret-color: #63ca21;
Left rule
Pull quote or callout
border-left: 4px solid #63ca21;
Ring + tint
Selected chip
background: #F0FBE9;
box-shadow: inset 0 0 0 2px #63ca21;
Conic badge
68%
background: conic-gradient(#63ca21 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #63ca21 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(99, 202, 33, 0.5)
rgb(99 202 33 / 50%)
#63ca2180
hsl(97 72% 46% / 50%)
color-mix(in srgb, #63ca21 50%, transparent)
Alpha8-digit hexFlat on white
10%#63ca211a#EFFAE9
20%#63ca2133#E0F4D3
40%#63ca2166#C1EAA6
60%#63ca2199#A1DF7A
80%#63ca21cc#82D54D

Gradients from #63ca21

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, #83E147, #63ca21 45%, #366E12);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #63ca21, #1DB052);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #63ca21, #8821CA);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #95E562 0%, #63ca21 45%, #366E12 100%);
Soft wash
Section backgrounds that stay readable
background: linear-gradient(180deg, #F7FAF4, #ffffff);
Mesh
Ambient background, no image weight
background: radial-gradient(60% 60% at 15% 20%, #DBE03F 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #2DDD4F 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #366E12 0%, transparent 65%), #63ca21;

Monochromatic scale

Palettes built from #63ca21

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.

#63ca21 in the real world

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

Industries
SustainabilityFinanceHealth and wellnessAgriculture
Common UI roles
ButtonsLinksFocus statesCharts
Print note

Converts to four-color process without much drama. Proof it anyway.

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 10.00:1.

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.

#63ca21, answered

What color is #63ca21?

#63ca21 is a balanced vivid green, closest to Lime Green (ΔE2000 4.3). It sits at 97° on the hue wheel with 72% saturation and 46% lightness, which reads as neutral.

What is the RGB value of #63ca21?

rgb(99, 202, 33) — 99 red, 202 green and 33 blue out of 255, or 38.8% / 79.2% / 12.9% by channel.

What is #63ca21 in HSL and HSV?

hsl(97, 72%, 46%) and hsv(97, 84%, 79%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #63ca21 a light or a dark color?

It is a mid-tone. Relative luminance is 0.4500 and perceived brightness is 64%, so black text on it reaches 10.00:1.

Should I use black or white text on #63ca21?

Black. It scores 10.00:1 against #63ca21, versus 2.10:1 for white — AAA at any size.

Is #63ca21 accessible on a white background?

#63ca21 on white scores 2.10:1, which fails WCAG AA at every size. Darken it to #418416 to reach 4.5:1, or #2F6110 for 7:1.

What is the complementary color of #63ca21?

#8821CA sits directly opposite on the wheel. Softer options are the split-complements #3421CA and #CA21B7, which give the same contrast with far less vibration.

What colors go well with #63ca21?

For interface work: #F7FAF4 as the surface, #D1EDC0 for borders, #6A9B4B for secondary text, #5D1CCF as an accent and #366E12 for hover and pressed states. For a palette, the analogous pair #B7CA21 and #21CA34 stays calm, while #8821CA is the loudest partner.

What is #63ca21 in CMYK for printing?

cmyk(51%, 0%, 84%, 21%). This is a screen-to-ink approximation — ask your printer for a proof before committing to a run.

Is #63ca21 warm or cool?

Neutral — it scores 53 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #A1CA21; nudged cooler, #23CC1F.

Which Tailwind color is closest to #63ca21?

The lime family — its 500 step is #84cc16, ΔE2000 4.3 away. That is a visible difference, so define #63ca21 as a custom token rather than reaching for the built-in.

How do I use #63ca21 in Tailwind CSS?

Inline it as an arbitrary value with bg-[#63ca21] or text-[#63ca21], 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 #63ca21 with 50% opacity?

rgba(99, 202, 33, 0.5), or #63ca2180 in eight-digit hex. Over white that composites to #B1E590; over black, #326511.

Is #63ca21 a web-safe color?

No. The nearest web-safe colour is #66CC33, ΔE2000 1.3 away. The palette only matters for legacy displays and some email clients now.

What does the color #63ca21 mean?

As a green, it reads safe, growing, natural. Green means go, well, and grown. It carries finance, sustainability and health with almost no explanation needed. At this chroma the effect is amplified — it will dominate whatever sits beside it.

What gradient works with #63ca21?

The safest is same-hue elevation: linear-gradient(135deg, #83E147, #63ca21 45%, #366E12). For more colour, a short hue run to #1DB052 keeps it rich without turning muddy.

Work with #63ca21 in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #63ca21 at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.