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green · cool

#01d721

a dark, electric green · cool · closest name: Lime Green

Token name suggestion: Shadow Basil

RGB
1, 215, 33
HSL
129°, 99%, 42%
CMYK
100, 0, 85, 16
Luminance
0.4872

#01d721 is a dark electric green, 129° on the wheel and 66/100 on the cool side. Put black text on it (10.74:1). As text it scores 1.95:1 on white — use #018615 instead. Nearest name is Lime Green, nearest Tailwind family is green.

hsl(129 99% 42%)rgb(1 215 33)Base step 700AAA inkCool

At a glance

Every number on this page in one read: what #01d721 is made of, how bright it looks, and which way it leans.

Hex
#01d721
Hue
129°
green
Saturation
99%
electric
Lightness
42%
dark
Brightness
84%
HSV value
Perceived
65%
weighted brightness
Luminance
0.4872
WCAG relative
Temperature
Cool
66/100 cool
Color family
Green
Tone
Electric
Best ink
Black
10.74:1
Closest name
Lime Green
ΔE2000 2.8
Chroma
101.5
LCH, 0–130ish
OKLCH L
0.763
perceptual lightness
Tailwind
green
500 · ΔE 8.4
Web-safe
#00CC33
nearest of 216
Where it sits
Hue129° of 360°
Saturation99%
Lightness42%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #01d721.

Temperature
Warm ← → Cool66% cool

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

Luminance by channel
Red0%
Green100%
Blue0%

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

Every format

HEX#01d721
HEX (8-digit)#01d721ff
RGBrgb(1, 215, 33)
RGBArgba(1, 215, 33, 1)
HSLhsl(129, 99%, 42%)
HSV / HSBhsv(129, 100%, 84%)
HWBhwb(129 0% 16%)
CMYKcmyk(100%, 0%, 85%, 16%)
LABlab(75.3 -74.8 68.5)
LCHlch(75.3 101.5 137.5)
OKLCHoklch(0.763 0.253 143.3)
XYZ (D65)xyz(24.59, 48.71, 9.55)
Decimal120609
Display P3color(display-p3 0.004 0.843 0.129)
Web-safe#00CC33

Copy-ready code

every platformclick to select
/* CSS */
color: #01d721;
background-color: #01d721;
/* CSS custom property */
--brand: #01d721;
/* Tailwind (arbitrary) */
class="text-[#01d721] bg-[#01d721]"
/* SCSS */
$brand: #01d721;
/* SwiftUI */
Color(red: 0.004, green: 0.843, blue: 0.129)
/* UIKit */
UIColor(red: 0.004, green: 0.843, blue: 0.129, alpha: 1)
/* Android XML */
<color name="brand">#01D721</color>
/* Android Compose */
Color(0xFF01D721)
/* Flutter */
Color(0xFF01D721)
/* Python / OpenCV (BGR) */
(33, 215, 1)
/* Python / PIL (RGB) */
(1, 215, 33)
/* Java AWT */
new Color(1, 215, 33)
/* .NET */
Color.FromArgb(255, 1, 215, 33)
/* OpenGL / Unity (0–1) */
(0.0039f, 0.8431f, 0.1294f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{1,215,33}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #01d721 85%, white);
border-color: color-mix(in oklab, #01d721 40%, transparent);
/* theme-aware in one line */
color: light-dark(#017F14, #D3EED7);
/* relative colour syntax */
--hover: hsl(from #01d721 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: #F1FEF3;
  --brand-100: #E3FCE7;
  --brand-200: #C0FBC9;
  --brand-300: #8FFEA0;
  --brand-400: #57FE70;
  --brand-500: #20FE41;
  --brand-600: #01F425;
  --brand-700: #01d721;
  --brand-800: #01A219;
  --brand-900: #057516;
  --brand-950: #03490E;
  --brand: #01d721;
  --brand-ink: #000000;
  --brand-surface: #F4FAF5;
  --brand-border: #C0EDC6;
  --brand-hover: #01B41C;
  --brand-pressed: #019016;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #142416;
    --brand-ink: #D3EED7;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F1FEF3',
        100: '#E3FCE7',
        200: '#C0FBC9',
        300: '#8FFEA0',
        400: '#57FE70',
        500: '#20FE41',
        600: '#01F425',
        700: '#01d721',
        800: '#01A219',
        900: '#057516',
        950: '#03490E',
        DEFAULT: '#01d721',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F1FEF3,
  '100': #E3FCE7,
  '200': #C0FBC9,
  '300': #8FFEA0,
  '400': #57FE70,
  '500': #20FE41,
  '600': #01F425,
  '700': #01d721,
  '800': #01A219,
  '900': #057516,
  '950': #03490E,
);
$brand-base: #01d721;
$brand-ink: #000000;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#F1FEF3", "$type": "color" },
      "100": { "$value": "#E3FCE7", "$type": "color" },
      "200": { "$value": "#C0FBC9", "$type": "color" },
      "300": { "$value": "#8FFEA0", "$type": "color" },
      "400": { "$value": "#57FE70", "$type": "color" },
      "500": { "$value": "#20FE41", "$type": "color" },
      "600": { "$value": "#01F425", "$type": "color" },
      "700": { "$value": "#01d721", "$type": "color" },
      "800": { "$value": "#01A219", "$type": "color" },
      "900": { "$value": "#057516", "$type": "color" },
      "950": { "$value": "#03490E", "$type": "color" }
    },
    "brandInk": { "$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 #01d721 · 10.74:1
Use #000000AAA at every size.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 1.95:1
AA fail · AA large fail · AAA fail
Aa
Black text · 10.74:1 · recommended
AA pass · AA large pass · AAA pass
Reading the other direction: #01d721 as text scores 1.95:1 on white and 10.74:1 on black.
Best tinted ink on it, if plain black or white feels flat: #017F14 at 2.65:1.

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
#018615 · 4.75:1
AA on white−16% L
#018615
The quick fox
#006810 · 7.03:1
AAA on white−22% L
#006810
The quick fox
#01d721 · 10.74:1
AA on blackalready passes
#01d721
The quick fox
#01d721 · 10.74:1
AAA on blackalready passes
#01d721

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #01AA1A 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
#01d721 on white: 1.95:1
AA ✗ fail · AA-large · AAA
Aa
#01d721 on black: 10.74:1
AA ✓ pass · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #01d721 as text on that neutral, and that neutral as text on #01d721.

NeutralRatioBoth directions
White1.95:1AaAa
Slate 501.87:1AaAa
Slate 1001.78:1AaAa
Slate 2001.59:1AaAa
Slate 3001.32:1AaAa
Slate 4001.31:1AaAa
Slate 5002.43:1AaAa
Slate 6003.88:1AaAa
Slate 7005.30:1AaAa
Slate 8007.48:1AaAa
Slate 9009.13:1AaAa
Black10.74:1AaAa
Colour vision deficiency
true color
protanopia · #DCC100
deuteranopia · #C9B43B
tritanopia · #00D1B7

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. #01d721 is pinned to step 700; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#F1FEF3
#E3FCE7
#C0FBC9
#8FFEA0
#57FE70
#20FE41
#01F425
#01d721
#01A219
#057516
#03490E
Base = 700Lightest = 50 · #F1FEF3Darkest = 950 · #03490EText 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 0.063 143.3);
  --brand-100: oklch(0.94 0.101 143.3);
  --brand-200: oklch(0.88 0.151 143.3);
  --brand-300: oklch(0.80 0.197 143.3);
  --brand-400: oklch(0.72 0.232 143.3);
  --brand-500: oklch(0.64 0.253 143.3);
  --brand-600: oklch(0.56 0.253 143.3);
  --brand-700: oklch(0.48 0.237 143.3);
  --brand-800: oklch(0.40 0.212 143.3);
  --brand-900: oklch(0.32 0.177 143.3);
  --brand-950: oklch(0.24 0.139 143.3);
}

Colors that work with #01d721

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#F4FAF5
Tinted page background
Border#C0EDC6
Hairlines and dividers
Muted text#4B9B57
Captions on the surface
Accent#C300D8
Second voice, not a rival
Dark variant#017F14
Hover, pressed, headers
Light variant#E6FFE9
Selected rows, tints
Dark surface#142416
Dark-mode background
Hover#01B41C
One step down in lightness
Pressed#019016
Two steps down
Disabled#90B896
Chroma pulled out
Focus ring#00ED23
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 #01d721

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
  • Headers, footers and dark-mode surfaces
  • Brand accents, badges and data highlights
Use with care
  • Text of any size on white — fails WCAG AA
  • Full-page backgrounds — tiring over long sessions
  • Black text placed on it
  • 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 #017F14
Safe as a 1px border on white
No — use #01AA1A

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.

At this chroma the association is amplified — it will dominate anything placed beside it, so give it space and use it sparingly. The low lightness adds weight and formality.

Worth knowing

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

Reads as
  • FormalityHigh
  • EnergyHigh
  • Weight58/100
  • TemperatureCool
  • ApproachabilityReserved

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#D701B7
Analogous left#4CD701
Analogous right#01D78C
Split-complement 1#8C01D7
Split-complement 2#D7014C
Triadic 1#2101D7
Triadic 2#D72101
Tetradic#014CD7
On the wheel
Base+30°−30°+120°+240°+180°129°

#01d721 sits at 129°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red0.4%
Green84.3%
Blue12.9%
R · 0–255
1
0x01
G · 0–255
215
0xd7
B · 0–255
33
0x21

CMYK percentages

Cyan99.5%
Magenta0.0%
Yellow84.7%
Key (black)15.7%

Total ink coverage is 200%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#01d721 text on a black background

contrast 10.74:1

Card sample

#01d721 text on a white background

contrast 1.95:1

Card sample

#01d721 on grey

1.78:1

#01d721 on its own surface

1.85:1

#01d721 on its dark surface

8.30:1

CSS3 live lab

Text font color

The quick brown fox

color: #01d721;
Background color
Panel with #01d721 background
background-color: #01d721;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #01d721;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(1, 215, 33, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(1, 215, 33, 0.45);
Border & gradient
Gradient panel
border: 3px solid #01d721;
background: linear-gradient(135deg, #01d721, #01D7B0);
Gradient text

Gradient headline

background: linear-gradient(90deg, #01d721, #01C9D7);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #01d721;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #01d721;
caret-color: #01d721;
Left rule
Pull quote or callout
border-left: 4px solid #01d721;
Ring + tint
Selected chip
background: #E6FFE9;
box-shadow: inset 0 0 0 2px #01d721;
Conic badge
68%
background: conic-gradient(#01d721 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #01d721 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(1, 215, 33, 0.5)
rgb(1 215 33 / 50%)
#01d72180
hsl(129 99% 42% / 50%)
color-mix(in srgb, #01d721 50%, transparent)
Alpha8-digit hexFlat on white
10%#01d7211a#E6FBE9
20%#01d72133#CCF7D3
40%#01d72166#99EFA6
60%#01d72199#67E77A
80%#01d721cc#34DF4D

Gradients from #01d721

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, #17FE3A, #01d721 45%, #017F14);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #01d721, #01B9A6);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #01d721, #D701B7);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #36FE54 0%, #01d721 45%, #017F14 100%);
Soft wash
Section backgrounds that stay readable
background: linear-gradient(180deg, #F4FAF5, #ffffff);
Mesh
Ambient background, no image weight
background: radial-gradient(60% 60% at 15% 20%, #76FE0D 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #01F6B4 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #017F14 0%, transparent 65%), #01d721;

Monochromatic scale

Palettes built from #01d721

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.

#01d721 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

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 10.74:1.

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.

#01d721, answered

What color is #01d721?

#01d721 is a dark electric green, closest to Lime Green (ΔE2000 2.8). It sits at 129° on the hue wheel with 99% saturation and 42% lightness, which reads as cool.

What is the RGB value of #01d721?

rgb(1, 215, 33) — 1 red, 215 green and 33 blue out of 255, or 0.4% / 84.3% / 12.9% by channel.

What is #01d721 in HSL and HSV?

hsl(129, 99%, 42%) and hsv(129, 100%, 84%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #01d721 a light or a dark color?

It is a mid-tone. Relative luminance is 0.4872 and perceived brightness is 65%, so black text on it reaches 10.74:1.

Should I use black or white text on #01d721?

Black. It scores 10.74:1 against #01d721, versus 1.95:1 for white — AAA at any size.

Is #01d721 accessible on a white background?

#01d721 on white scores 1.95:1, which fails WCAG AA at every size. Darken it to #018615 to reach 4.5:1, or #006810 for 7:1.

What is the complementary color of #01d721?

#D701B7 sits directly opposite on the wheel. Softer options are the split-complements #8C01D7 and #D7014C, which give the same contrast with far less vibration.

What colors go well with #01d721?

For interface work: #F4FAF5 as the surface, #C0EDC6 for borders, #4B9B57 for secondary text, #C300D8 as an accent and #017F14 for hover and pressed states. For a palette, the analogous pair #4CD701 and #01D78C stays calm, while #D701B7 is the loudest partner.

What is #01d721 in CMYK for printing?

cmyk(100%, 0%, 85%, 16%). 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 #01d721 warm or cool?

Cool — it scores 66 on a scale where 0 is the warmest orange and 100 the coolest azure. Nudged warmer it becomes #2FD701; nudged cooler, #00D870.

Which Tailwind color is closest to #01d721?

The green family — its 500 step is #22c55e, ΔE2000 8.4 away. That is a visible difference, so define #01d721 as a custom token rather than reaching for the built-in.

How do I use #01d721 in Tailwind CSS?

Inline it as an arbitrary value with bg-[#01d721] or text-[#01d721], 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 #01d721 with 50% opacity?

rgba(1, 215, 33, 0.5), or #01d72180 in eight-digit hex. Over white that composites to #80EB90; over black, #016C11.

Is #01d721 a web-safe color?

No. The nearest web-safe colour is #00CC33, ΔE2000 3.2 away. The palette only matters for legacy displays and some email clients now.

What does the color #01d721 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 #01d721?

The safest is same-hue elevation: linear-gradient(135deg, #17FE3A, #01d721 45%, #017F14). For more colour, a short hue run to #01B9A6 keeps it rich without turning muddy.

Work with #01d721 in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #01d721 at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.