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green · cool

#128521

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

Token name suggestion: Shadow Moss

RGB
18, 133, 33
HSL
128°, 76%, 30%
CMYK
87, 0, 75, 48
Luminance
0.1701

#128521 is a dark electric green, 128° on the wheel and 66/100 on the cool side. Put white text on it (4.77:1). As text it scores 4.77:1 on white — safe at any size. Nearest name is Forest Green, nearest Tailwind family is green.

hsl(128 76% 30%)rgb(18 133 33)Base step 800AA inkCool

At a glance

Every number on this page in one read: what #128521 is made of, how bright it looks, and which way it leans.

Hex
#128521
Hue
128°
green
Saturation
76%
electric
Lightness
30%
dark
Brightness
52%
HSV value
Perceived
40%
weighted brightness
Luminance
0.1701
WCAG relative
Temperature
Cool
66/100 cool
Color family
Green
Tone
Electric
Best ink
White
4.77:1
Closest name
Forest Green
ΔE2000 2.4
Chroma
65.8
LCH, 0–130ish
OKLCH L
0.538
perceptual lightness
Tailwind
green
500 · ΔE 20
Web-safe
#009933
nearest of 216
Where it sits
Hue128° of 360°
Saturation76%
Lightness30%
Saturation × lightness field

Left edge is grey, right edge is full chroma; top is white, bottom is black. The dot is #128521.

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
Red1%
Green99%
Blue1%

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

Every format

HEX#128521
HEX (8-digit)#128521ff
RGBrgb(18, 133, 33)
RGBArgba(18, 133, 33, 1)
HSLhsl(128, 76%, 30%)
HSV / HSBhsv(128, 86%, 52%)
HWBhwb(128 7% 48%)
CMYKcmyk(87%, 0%, 75%, 48%)
LABlab(48.3 -49.9 43.0)
LCHlch(48.3 65.8 139.3)
OKLCHoklch(0.538 0.166 144.1)
XYZ (D65)xyz(8.91, 17.01, 4.25)
Decimal1213729
Display P3color(display-p3 0.071 0.522 0.129)
Web-safe#009933

Copy-ready code

every platformclick to select
/* CSS */
color: #128521;
background-color: #128521;
/* CSS custom property */
--brand: #128521;
/* Tailwind (arbitrary) */
class="text-[#128521] bg-[#128521]"
/* SCSS */
$brand: #128521;
/* SwiftUI */
Color(red: 0.071, green: 0.522, blue: 0.129)
/* UIKit */
UIColor(red: 0.071, green: 0.522, blue: 0.129, alpha: 1)
/* Android XML */
<color name="brand">#128521</color>
/* Android Compose */
Color(0xFF128521)
/* Flutter */
Color(0xFF128521)
/* Python / OpenCV (BGR) */
(33, 133, 18)
/* Python / PIL (RGB) */
(18, 133, 33)
/* Java AWT */
new Color(18, 133, 33)
/* .NET */
Color.FromArgb(255, 18, 133, 33)
/* OpenGL / Unity (0–1) */
(0.0706f, 0.5216f, 0.1294f, 1f)
/* LaTeX */
\definecolor{brand}{RGB}{18,133,33}
modern cssclick to select
/* mix without leaving CSS */
background: color-mix(in oklab, #128521 85%, white);
border-color: color-mix(in oklab, #128521 40%, transparent);
/* theme-aware in one line */
color: light-dark(#0F701C, #D3EED6);
/* relative colour syntax */
--hover: hsl(from #128521 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: #F3FCF4;
  --brand-100: #E7F9E9;
  --brand-200: #C8F4CD;
  --brand-300: #9CF2A7;
  --brand-400: #6BEB7B;
  --brand-500: #39E450;
  --brand-600: #1DD835;
  --brand-700: #18B42C;
  --brand-800: #128521;
  --brand-900: #12681D;
  --brand-950: #0B4112;
  --brand: #128521;
  --brand-ink: #ffffff;
  --brand-surface: #F4FAF5;
  --brand-border: #C0EDC6;
  --brand-hover: #0E6619;
  --brand-pressed: #094611;
}
@media (prefers-color-scheme: dark) {
  :root {
    --brand-surface: #142416;
    --brand-ink: #D3EED6;
  }
}
tailwind.config.jsclick to select
theme: {
  extend: {
    colors: {
      brand: {
        50: '#F3FCF4',
        100: '#E7F9E9',
        200: '#C8F4CD',
        300: '#9CF2A7',
        400: '#6BEB7B',
        500: '#39E450',
        600: '#1DD835',
        700: '#18B42C',
        800: '#128521',
        900: '#12681D',
        950: '#0B4112',
        DEFAULT: '#128521',
      },
    },
  },
}
scss mapclick to select
$brand: (
  '50': #F3FCF4,
  '100': #E7F9E9,
  '200': #C8F4CD,
  '300': #9CF2A7,
  '400': #6BEB7B,
  '500': #39E450,
  '600': #1DD835,
  '700': #18B42C,
  '800': #128521,
  '900': #12681D,
  '950': #0B4112,
);
$brand-base: #128521;
$brand-ink: #ffffff;

@function brand($step) { @return map-get($brand, $step); }
w3c design tokens (json)click to select
{
  "color": {
    "brand": {
      "50": { "$value": "#F3FCF4", "$type": "color" },
      "100": { "$value": "#E7F9E9", "$type": "color" },
      "200": { "$value": "#C8F4CD", "$type": "color" },
      "300": { "$value": "#9CF2A7", "$type": "color" },
      "400": { "$value": "#6BEB7B", "$type": "color" },
      "500": { "$value": "#39E450", "$type": "color" },
      "600": { "$value": "#1DD835", "$type": "color" },
      "700": { "$value": "#18B42C", "$type": "color" },
      "800": { "$value": "#128521", "$type": "color" },
      "900": { "$value": "#12681D", "$type": "color" },
      "950": { "$value": "#0B4112", "$type": "color" }
    },
    "brandInk": { "$value": "#ffffff", "$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#ffffff on #128521 · 4.77:1
Use #ffffffAA at every size, AAA for large text only.
Aa
12px
Aa
16px
Aa
24px
Aa
White text · 4.77:1 · recommended
AA pass · AA large pass · AAA fail
Aa
Black text · 4.40:1
AA fail · AA large pass · AAA fail
Reading the other direction: #128521 as text scores 4.77:1 on white and 4.40:1 on black.
Best tinted ink on it, if plain black or white feels flat: #E9FCEB at 4.45:1.

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
#128521 · 4.77:1
AA on whitealready passes
#128521
The quick fox
#0E6619 · 7.16:1
AAA on white−7% L
#0E6619
The quick fox
#138922 · 4.63:1
AA on black+1% L
#138922
The quick fox
#17AD2B · 7.05:1
AAA on black+9% L
#17AD2B

Large text — 24px regular or 18.66px bold and above — only needs 3:1, so #128521 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
#128521 on white: 4.77:1
AA ✓ pass · AA-large · AAA
Aa
#128521 on black: 4.40:1
AA ✗ fail · AA-large · AAA
Against the neutral ladder

Contrast is symmetric, so each row covers both directions: #128521 as text on that neutral, and that neutral as text on #128521.

NeutralRatioBoth directions
White4.77:1AaAa
Slate 504.56:1AaAa
Slate 1004.35:1AaAa
Slate 2003.87:1AaAa
Slate 3003.21:1AaAa
Slate 4001.86:1AaAa
Slate 5001.00:1AaAa
Slate 6001.59:1AaAa
Slate 7002.17:1AaAa
Slate 8003.07:1AaAa
Slate 9003.74:1AaAa
Black4.40:1AaAa
Colour vision deficiency
true color
protanopia · #88780F
deuteranopia · #7C6F2C
tritanopia · #008172

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. #128521 is pinned to step 800; the rest hold its hue and let saturation ease off at the extremes so the pale end never turns neon.

#F3FCF4
#E7F9E9
#C8F4CD
#9CF2A7
#6BEB7B
#39E450
#1DD835
#18B42C
#128521
#12681D
#0B4112
Base = 800Lightest = 50 · #F3FCF4Darkest = 950 · #0B4112Text step on white = 800
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 0.042 144.1);
  --brand-100: oklch(0.94 0.067 144.1);
  --brand-200: oklch(0.88 0.100 144.1);
  --brand-300: oklch(0.80 0.130 144.1);
  --brand-400: oklch(0.72 0.153 144.1);
  --brand-500: oklch(0.64 0.166 144.1);
  --brand-600: oklch(0.56 0.166 144.1);
  --brand-700: oklch(0.48 0.156 144.1);
  --brand-800: oklch(0.40 0.140 144.1);
  --brand-900: oklch(0.32 0.116 144.1);
  --brand-950: oklch(0.24 0.092 144.1);
}

Colors that work with #128521

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

Text on it#ffffff
White wins here
Surface#F4FAF5
Tinted page background
Border#C0EDC6
Hairlines and dividers
Muted text#4B9B55
Captions on the surface
Accent#790F88
Second voice, not a rival
Dark variant#0F701C
Hover, pressed, headers
Light variant#E9FCEB
Selected rows, tints
Dark surface#142416
Dark-mode background
Hover#0E6619
One step down in lightness
Pressed#094611
Two steps down
Disabled#689F6F
Chroma pulled out
Focus ring#0CA01F
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 #128521

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

Works well for
  • Body text and links on white
  • 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
  • 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
Any size
Safe as a fill behind white type
Yes
Safe as a 1px border on white
Yes

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
  • Weight70/100
  • 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#851276
Analogous left#3D8512
Analogous right#12855A
Split-complement 1#5A1285
Split-complement 2#85123D
Triadic 1#211285
Triadic 2#852112
Tetradic#123D85
On the wheel
Base+30°−30°+120°+240°+180°128°

#128521 sits at 128°. Every dot is a harmony position and links to its own page in the table alongside.

RGB percentages

Red7.1%
Green52.2%
Blue12.9%
R · 0–255
18
0x12
G · 0–255
133
0x85
B · 0–255
33
0x21

CMYK percentages

Cyan86.5%
Magenta0.0%
Yellow75.2%
Key (black)47.8%

Total ink coverage is 210%. Most commercial presses cap around 300% — above that, sheets stop drying properly.

Color previews

#128521 text on a black background

contrast 4.40:1

Card sample

#128521 text on a white background

contrast 4.77:1

Card sample

#128521 on grey

4.35:1

#128521 on its own surface

4.51:1

#128521 on its dark surface

3.40:1

CSS3 live lab

Text font color

The quick brown fox

color: #128521;
Background color
Panel with #128521 background
background-color: #128521;
Text shadow — hex

Glowing headline

text-shadow: 2px 2px 8px #128521;
Text shadow — RGB

Soft neon halo

text-shadow: 0 0 14px rgba(18, 133, 33, 0.45);
Div box shadow
Elevated card
box-shadow: 0 12px 32px -8px rgba(18, 133, 33, 0.45);
Border & gradient
Gradient panel
border: 3px solid #128521;
background: linear-gradient(135deg, #128521, #12856E);
Gradient text

Gradient headline

background: linear-gradient(90deg, #128521, #128085);
-webkit-background-clip: text;
color: transparent;
Focus ring
Focused control
outline: 2px solid #128521;
outline-offset: 3px;
Underline & caret

Marked up text

text-decoration-color: #128521;
caret-color: #128521;
Left rule
Pull quote or callout
border-left: 4px solid #128521;
Ring + tint
Selected chip
background: #E9FCEB;
box-shadow: inset 0 0 0 2px #128521;
Conic badge
68%
background: conic-gradient(#128521 68%, #e2e8f0 0);

Transparency

What each alpha value actually composites to. The top row is #128521 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(18, 133, 33, 0.5)
rgb(18 133 33 / 50%)
#12852180
hsl(128 76% 30% / 50%)
color-mix(in srgb, #128521 50%, transparent)
Alpha8-digit hexFlat on white
10%#1285211a#E7F3E9
20%#12852133#D0E7D3
40%#12852166#A0CEA6
60%#12852199#71B67A
80%#128521cc#419D4D

Gradients from #128521

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, #19BB2E, #128521 45%, #0F701C);
Duotone
A short hue run reads richer than a flat fill
background: linear-gradient(120deg, #128521, #0E6A5F);
Complement sweep
Loud — keep it behind large type only
background: linear-gradient(90deg, #128521, #851276);
Spotlight
Hero panels and app headers
background: radial-gradient(120% 120% at 20% 0%, #1DD635 0%, #128521 45%, #0F701C 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%, #5EB218 0%, transparent 60%), radial-gradient(55% 55% at 85% 15%, #16A078 0%, transparent 60%), radial-gradient(70% 70% at 50% 95%, #0F701C 0%, transparent 65%), #128521;

Monochromatic scale

Palettes built from #128521

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.

#128521 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

Too dim on dark surfaces at 4.40:1 — lift it to #138922 for body text, or reserve it for fills.

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.

#128521, answered

What color is #128521?

#128521 is a dark electric green, closest to Forest Green (ΔE2000 2.4). It sits at 128° on the hue wheel with 76% saturation and 30% lightness, which reads as cool.

What is the RGB value of #128521?

rgb(18, 133, 33) — 18 red, 133 green and 33 blue out of 255, or 7.1% / 52.2% / 12.9% by channel.

What is #128521 in HSL and HSV?

hsl(128, 76%, 30%) and hsv(128, 86%, 52%). HSL is what CSS takes; HSV is what your design tool's picker shows, which is why the saturation numbers rarely match.

Is #128521 a light or a dark color?

It is a dark color. Relative luminance is 0.1701 and perceived brightness is 40%, so white text on it reaches 4.77:1.

Should I use black or white text on #128521?

White. It scores 4.77:1 against #128521, versus 4.40:1 for black — AA at any size.

Is #128521 accessible on a white background?

#128521 on white scores 4.77:1, which clears AA at every size but not AAA.

What is the complementary color of #128521?

#851276 sits directly opposite on the wheel. Softer options are the split-complements #5A1285 and #85123D, which give the same contrast with far less vibration.

What colors go well with #128521?

For interface work: #F4FAF5 as the surface, #C0EDC6 for borders, #4B9B55 for secondary text, #790F88 as an accent and #0F701C for hover and pressed states. For a palette, the analogous pair #3D8512 and #12855A stays calm, while #851276 is the loudest partner.

What is #128521 in CMYK for printing?

cmyk(87%, 0%, 75%, 48%). 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 #128521 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 #2D8512; nudged cooler, #10874B.

Which Tailwind color is closest to #128521?

The green family — its 500 step is #22c55e, ΔE2000 20 away. That is a visible difference, so define #128521 as a custom token rather than reaching for the built-in.

How do I use #128521 in Tailwind CSS?

Inline it as an arbitrary value with bg-[#128521] or text-[#128521], 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 #128521 with 50% opacity?

rgba(18, 133, 33, 0.5), or #12852180 in eight-digit hex. Over white that composites to #89C290; over black, #094311.

Is #128521 a web-safe color?

No. The nearest web-safe colour is #009933, ΔE2000 7 away. The palette only matters for legacy displays and some email clients now.

What does the color #128521 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 #128521?

The safest is same-hue elevation: linear-gradient(135deg, #19BB2E, #128521 45%, #0F701C). For more colour, a short hue run to #0E6A5F keeps it rich without turning muddy.

Work with #128521 in the Color Lab

Every tool opens with this colour already loaded.

Every value on this page is computed from #128521 at request time — conversions, contrast ratios and ΔE distances are calculated, never looked up.