Chartreuse3
chartreuse3 · #66CD00
HEX
#66CD00
RGB
rgb(102, 205, 0)
CMYK
cmyk(50%, 0%, 100%, 20%)
HSL
hsl(90, 100%, 40%)
LAB
lab(73.9, -57.4, 72.8)
What is Chartreuse3?
Chartreuse3 is the chartreuse3 reference in the X11 named colors. Its sRGB value is #66CD00 (rgb 102, 205, 0). It sits in the green family. Historical X Window System color names — the numbered 1-4 lightness variants of the classic xorg-server rgb.txt palette. See disclaimer for accuracy and trademark notes.
Accessibility
WCAG 2.1 contrast checks for Chartreuse3 as a background.
Black text on this color
White text on this color
Shades, tints & tonal scale of Chartreuse3
An 11-step tonal scale derived from Chartreuse3 (#66CD00). Click any swatch to copy its HEX. Use these as a starting point for design tokens, hover states, and disabled states in a design system.
50
#F3FBEB
#F3FBEB
100
#E7F7D6
#E7F7D6
200
#CEEFAD
#CEEFAD
300
#B3E680
#B3E680
400
#8CDA40
#8CDA40
500
#66CD00
#66CD00
600
#57AE00
#57AE00
700
#428500
#428500
800
#2E5C00
#2E5C00
900
#1A3300
#1A3300
950
#0C1900
#0C1900
Lighter tints (mixed with white)
15%
#8CD66C
30%
#A8DE95
45%
#BFE5B3
60%
#D3EDCB
75%
#E5F4E1
Darker shades (mixed with black)
15%
#5EBF00
30%
#56AF00
45%
#4C9D00
60%
#418700
75%
#336D00
Color harmonies for Chartreuse3
Classic color-theory harmonies derived from rotating the hue of Chartreuse3. Use these to build accent palettes, brand systems, and accessible UI color pairings.
Complementary
180° opposite — strongest contrast
#66CD00
#66CD00
#6600CC
#6600CC
Triadic
Three colors 120° apart
#66CD00
#66CD00
#0066CC
#0066CC
#CC0066
#CC0066
Analogous
Two neighbors ±30° on the wheel
#CCCC00
#CCCC00
#66CD00
#66CD00
#00CC00
#00CC00
Split-complementary
Base + two colors flanking its complement
#66CD00
#66CD00
#0000CC
#0000CC
#CC00CC
#CC00CC
Tetradic
Two complementary pairs
#66CD00
#66CD00
#00CC66
#00CC66
#6600CC
#6600CC
#CC0066
#CC0066
Square
Four colors evenly spaced 90° apart
#66CD00
#66CD00
#00CCCC
#00CCCC
#6600CC
#6600CC
#CC0000
#CC0000
Chartreuse3 in every color space
Full conversion of Chartreuse3 across the color spaces designers and developers actually use — including OKLCH (the perceptually-uniform space that powers Tailwind v4 and CSS Color Module Level 4) and HWB.
HEX
#66CD00
RGB
rgb(102, 205, 0)
CMYK
cmyk(50%, 0%, 100%, 20%)
HSL
hsl(90, 100%, 40%)
HSV
hsv(90, 100%, 80%)
HWB
hwb(90 0% 20%)
CIE Lab
lab(73.9 -57.4 72.8)
OKLCH
oklch(75.6% 0.224 135.8)
XYZ (D65)
xyz(27.31, 46.49, 7.53)
Copy-ready code for Chartreuse3
Drop-in snippets for CSS, Tailwind, Sass, iOS Swift, and Android XML. Click the copy button on any snippet to put it on your clipboard.
CSS
color: #66CD00;
background-color: #66CD00;CSS variable
:root {
--color-chartreuse3: #66CD00;
}Tailwind config
// tailwind.config.js
colors: {
'chartreuse3': '#66CD00',
}Sass
$color-chartreuse3: #66CD00;Swift UIColor
UIColor(red: 0.400, green: 0.804, blue: 0.000, alpha: 1.0)Android XML
<color name="chartreuse3">#66CD00</color>Closest match in every color system
The nearest Chartreuse3 equivalent in every other color system on this site, ranked by ΔE2000 perceptual distance. Useful when translating between design-system, web-standard, and industrial color references.
Closest in X11 named colors
Top 6 ΔE2000-closest entries within the same collection.
Closest Pantone matches
Top 6 ΔE2000-closest Pantone references. Cross-system matching is approximate — see disclaimer.
Closest RAL Classic matches
Top 6 ΔE2000-closest RAL Classic references for industrial coating cross-reference.
RAL 6018
#57A639
Yellow green
RAL 6021
#89AC76
Pale green
RAL 1000
#BEBD7F
Green beige
RAL 6019
#BDECB6
Pastel green
RAL 6017
#4C9141
May green
RAL 1016
#EDFF21
Sulfur yellow
FAQ about Chartreuse3
What is the HEX code for Chartreuse3?
Chartreuse3 (chartreuse3) has the HEX code #66CD00. In RGB it is rgb(102, 205, 0), and in CMYK it is cmyk(50%, 0%, 100%, 20%).
What is the OKLCH value of Chartreuse3?
Chartreuse3 converts to oklch(0.756 0.224 135.8). OKLCH is the perceptually uniform color space used by Tailwind v4 and CSS Color Module Level 4.
Is Chartreuse3 accessible for body text?
Used as a background, Chartreuse3 has a contrast ratio of 10.30:1 with black text and 2.04:1 with white text. WCAG 2.1 AA requires 4.5:1 for normal text. The current recommendation is to use black text and verify in real UI context.
What is the closest Pantone to Chartreuse3?
The closest Pantone reference to Chartreuse3 by ΔE2000 perceptual distance is Pantone 368 C (#78BE20). Cross-system Pantone matching is approximate; for color-critical print work, verify with a physical Pantone guide.
What is the closest RAL color to Chartreuse3?
The closest RAL Classic reference to Chartreuse3 by ΔE2000 distance is RAL 6018 (Yellow green, #57A639). RAL is a German industrial coating standard commonly used for paint, powder coat, and architectural specification.
What is the complementary color of Chartreuse3?
The complementary color (180° opposite on the HSL color wheel) of Chartreuse3 is #6600CC. Use it for high-contrast accents, error states, or call-to-action pairings.
Data provenance & source
X11 named colors (xorg rgb.txt)
The historical X11 color name list shipped in the xorg-server rgb.txt file. Roughly 550 entries covering classic computing color names like 'PapayaWhip', 'MediumAquamarine', and 'DarkSlateGray'. Many CSS named colors originate here. Use as a reference for legacy and creative color names. Most modern CSS implementations accept these names directly.
- Source type
- derived
- Confidence
- high
- License
- MIT/X11 license (X Consortium)
- Last reviewed
- 2026-05-24
Workflow tags
X11 colors are sRGB digital values from a 1980s color system. For print, convert to a process-appropriate color and proof against substrate.