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Erin

#00FF40·green family·WCAG AAA

Tints & Shades

50

100

200

300

400

500

600

700

800

900

Scale from white (50) through Erin (500) to black (900), interpolated in Lab color space.

Color Values

HEX
#00FF40
RGB
rgb(0, 255, 64)
HSL
hsl(135, 100%, 50%)
OKLCH
oklch(0.868 0.278 144)
CMYK
cmyk(100%, 0%, 75%, 0%)
Luminance:0.7189
CSS var:--color-erin
Tailwind:bg-[#00FF40]

Accessibility

Score: 48/100

On White (#FFF)

1.37:1

Fail

On Black (#000)

15.38:1

AAA

On Light Gray (#F5F5F5)

1.25:1

Fail

Best text color on this background:

black15.38:1
Open in Contrast Checker →

Design Applications

Background

background-color: #00FF40

Text Color

color: #00FF40

bg-[#00FF40] text-[#000000]

Accent border card component

border-left: 4px solid #00FF40

Color Meaning & Psychology

Green occupies the center of the visible spectrum where the eye is most sensitive, making it the easiest color to process — literally restful for the eye. Green's associations with nature, growth, and fresh produce are deeply biological, rooted in the evolutionary advantage of finding food. In finance, "going green" means profit. In design, green signals health, sustainability, and natural ingredients. Darker greens evoke prestige and reliability; lighter greens feel fresh and energetic; blue-greens feel sophisticated and trustworthy. Green is uniquely cross-cultural in positive associations, though it represents environmental risk in some financial contexts. At medium lightness, it is the most versatile tone of this hue family — readable as text on light backgrounds, yet vibrant enough as a visual accent.

Industry Usage

Common contexts and industries where Erin is applied in professional design.

  • Financial services and investment platforms
  • Health, wellness, and organic food brands
  • Environmental and sustainability organizations
  • Pharmaceutical and medical products
  • Agriculture and farming brands
  • Eco-friendly consumer goods
  • Real estate and property development
  • Success and achievement badges in UI

Accessibility Considerations

Normal Text

Fails AA

4.5:1 minimum required

Large Text

Fails AA Large

3:1 minimum required

UI Components

Check contrast

3:1 for non-text UI

Erin is a light color. Use black (#000000) text on top of it for maximum readability (15.38:1). Avoid white text on this background.

CSS & Code Examples

Background

background-color: #00FF40;

Text

color: #00FF40;

Border

border: 2px solid #00FF40;

Box Shadow

box-shadow: 0 4px 20px #00FF4040;

Gradient

background: linear-gradient(135deg, #00FF40, #6fff76);

Tailwind-style

--color-erin: #00FF40;

Tailwind CSS Utilities

Use arbitrary value syntax in Tailwind CSS to apply Erin without a custom config.

Background

bg-[#00FF40]

Text

text-[#00FF40]

Border

border-[#00FF40]

Ring

ring-[#00FF40]

Fill

fill-[#00FF40]

From (gradient)

from-[#00FF40]

Via (gradient)

via-[#00FF40]

To (gradient)

to-[#00FF40]

Design Tokens

Ready-to-use Erin design token in CSS custom properties, SCSS, Tailwind v3/v4, and JSON formats.

CSS Custom Properties

:root {
  --color-erin: #00FF40;
  --color-erin-rgb: 0, 255, 64;
  --color-erin-hsl: 135, 100%, 50%;
}

SCSS Variables

$color-erin: #00FF40;
$color-erin-rgb: 0, 255, 64;
$color-erin-hsl: 135, 100%, 50%;

Tailwind v3 Config

// tailwind.config.js
module.exports = {
  theme: {
    extend: {
      colors: {
        'erin': '#00FF40',
      },
    },
  },
};

Tailwind v4 (@theme)

/* tailwind.css */
@theme {
  --color-erin: #00FF40;
}

JSON Design Token (W3C format)

{
  "erin": {
    "value": "#00FF40",
    "type": "color",
    "description": "Erin — #00FF40"
  }
}

What Does Erin Mean? Color Psychology & Cultural Symbolism

The psychology of Erin runs through two distinct channels: the primal register of growth and nature, and the cultural layer of health, prosperity, and permission. At #00FF40, this shade settles into growth—drawing on both channels to create a response that's stable, reassuring, and positive.

  • Across color psychology research, green consistently tests high for "health" associations, making Erin a reliable vehicle for growth in cross-demographic audiences.
  • Brand designers draw on green-family tones to project trustworthiness and reliability—values that Erin communicates in a medium key.
  • At 100% saturation, Erin reads as vivid—Electric and lime greens are among the most energetic hues in the spectrum—striking, modern, and attention-commanding, used in sports, gaming, and tech-forward branding.
  • Erin's medium lightness (50%) shifts its psychological register: a balanced mid-tone that embodies growth, nature, health, and balance at its most direct.

The enduring power of Erin is that it never needs to explain itself—growth, health, and permission are universally understood.

How to Use Erin in Design: Applications, Pairings & Best Practices

The design applications of Erin span from digital UI states to full brand identity systems. Its vivid saturation (100%) means it reads as a high-energy presence that demands attention in any composition in both contexts—mid-weight applications including UI components, icons, and moderate-emphasis text elements in background uses, more active as an accent.

  • Avoid: warning or danger contexts (except for safety signs), over-saturated versions in premium luxury branding, and contexts requiring urgency.
  • Color harmonies: Erin's complementary color creates a high-energy split ideal for promotional design; its analogous palette (±30° hue) builds cohesive, monochromatic sophistication.
  • Proportional use: Erin's vivid saturation (100%) means small applications—accents, highlights, icons—deliver maximum impact without visual fatigue. Reserve large-scale use for intentional brand moments.
  • Erin creates strong legibility with black text overlays (15.4:1 contrast ratio), making it a reliable background or surface color in design systems
  • Typography: Erin as text requires a dark background; its 50% lightness means it provides 1.4:1 contrast on white, not meeting WCAG AA.

The enduring power of Erin is that it never needs to explain itself—growth, health, and permission are universally understood.

Erin Accessibility: WCAG Contrast Ratios, Color Blindness & Inclusive Design

Erin (#00FF40) achieves a 15.38:1 contrast ratio with black text, surpassing the WCAG 2.1 AAA threshold of 7:1. This exceptional contrast qualifies it for body text, UI components at any size, and all accessibility-sensitive interface contexts. Relative luminance: 71.9%.

  • As text on white (#FFFFFF): 1.37:1 — Fail
  • As text on black (#000000): 15.38:1 — AAA ✓
  • Best text color on Erin background: Black (#000000) at 15.38:1
  • WCAG 2.1 luminance: 71.9% — high-luminance (near-white)—it provides excellent readability for dark text overlays and integrates naturally into light design systems
  • Erin qualifies for all text sizes including small body copy (AAA).

Erin's WCAG profile makes it a compliant choice for most text applications.

Erin in Industry: Branding, Design & Market Applications

Erin (#00FF40) is most at home in industries where growth, nature, health, and balance are key brand values. Its medium quality makes it particularly effective in Healthcare & Wellness contexts, where the vivid saturation signals balance at exactly the right register.

  • Healthcare & Wellness: Green's association with health, nature, and healing makes it the second-most-common color in healthcare branding (after blue). It signals vitality, recovery, and natural wellness without the clinical coldness of pure white or blue. (examples: CVS Health, Mayo Clinic, Kaiser Permanente) Works best in teal-green and sage variations for digital health products; more saturated greens suit fitness and sports medicine.
  • Finance & Banking: In Western markets, the green-money association is deeply embedded. Financial institutions use dark, sophisticated greens to communicate growth, prosperity, and fiduciary reliability. It's equally effective for positive portfolio indicators and "go" confirmation states in trading UIs. (examples: JPMorgan Chase, Goldman Sachs, Visa) Dark greens with gold accents signal premium financial services; bright greens in fintech apps signal growth metrics.
  • Sustainability & Organic: Green is the categorical color of environmental consciousness. Sustainability brands, organic food labels, and clean-energy companies use it as an immediate, unambiguous signal of ecological values and natural origin. (examples: Patagonia, Allbirds, Grove Collaborative) The challenge is differentiation—nearly every sustainability brand uses green, so typography, illustration style, and specific tone matter more.
  • Brand positioning: Erin is best suited for brands projecting health, sustainability, growth. Categories outside this positioning—warning or danger contexts (except for safety signs)—tend to see weaker results.
  • Adjacent applications: Beyond primary industries, Erin works effectively in success states, approval indicators, sustainability branding—contexts where balance serves a secondary but reinforcing role.

The industries where Erin performs best are those where the audience expects balance. Build brand strategy around this alignment, not against it.

Frequently Asked Questions

What is the hex code for Erin?
The hex code for Erin is #00FF40. Its RGB values are rgb(0, 255, 64) and its HSL values are hsl(135, 100%, 50%).
What does Erin mean in design?
Green occupies the center of the visible spectrum where the eye is most sensitive, making it the easiest color to process — literally restful for the eye. Green's associations with nature, growth, and fresh produce are deeply biological, rooted in the evolutionary advantage of finding food. In finance, "going green" means profit. In design, green signals health, sustainability, and natural ingredients. Darker greens evoke prestige and reliability; lighter greens feel fresh and energetic; blue-greens feel sophisticated and trustworthy. Green is uniquely cross-cultural in positive associations, though it represents environmental risk in some financial contexts. At medium lightness, it is the most versatile tone of this hue family — readable as text on light backgrounds, yet vibrant enough as a visual accent.
Is Erin WCAG accessible?
Erin (#00FF40) does not pass WCAG AA on white (1.37:1 ratio). Use it on dark backgrounds where it achieves 15.38:1. Its overall accessibility score is 48/100.
What colors go well with Erin?
Erin pairs well with its complementary color Shocking Pink (#FC0FC0). Analogous colors like Harlequin and Green also work harmoniously. Check the Color Harmonies section above for the full palette.
What is Erin used for?
Erin is commonly used for: Financial services and investment platforms; Health, wellness, and organic food brands; Environmental and sustainability organizations; Pharmaceutical and medical products; Agriculture and farming brands.
What are the CSS and Tailwind values for Erin?
In CSS, use `color: #00FF40` or `background-color: #00FF40`. The CSS custom property is `--color-erin: #00FF40`. In Tailwind CSS, use the arbitrary value class `bg-[#00FF40]` for backgrounds or `text-[#00FF40]` for text.