#moonbit-color

#Features

#Color Spaces

• RGB - Red, Green, Blue (0.0-1.0 or 0-255)
• HSL - Hue, Saturation, Lightness
• HSV - Hue, Saturation, Value
• Hex - Hexadecimal color strings (#RRGGBB)

#Core Capabilities

• ✅ Color space conversions (RGB ↔ HSL ↔ HSV ↔ Hex)
• ✅ Color interpolation (linear, hue-aware)
• ✅ Gradient generation (2-color and multi-stop)
• ✅ WCAG 2.1 contrast ratio calculation
• ✅ Accessibility compliance checking (AA/AAA)
• ✅ Palette generation (analogous, complementary, triadic, tetradic, monochromatic, split-complementary)

#Installation

moon add weedmind-6812/moonbit-color

#Quick Start

#Basic Color Creation

// From RGB integers (0-255)
let orange = @color.RGB::from_int(255, 165, 0)

// From hex string
let blue = @color.RGB::from_hex("#0080FF")

// Convert to hex
println(orange.to_hex())  // "#FFA500"

#Color Space Conversions

let rgb = @color.RGB::from_int(255, 87, 51)

// RGB to HSL
let hsl = rgb.to_hsl()
println("H: " + hsl.h.to_string())  // Hue: 0-360

// HSL back to RGB
let rgb2 = hsl.to_rgb()

// RGB to HSV
let hsv = rgb.to_hsv()

#Color Interpolation

let red = @color.RGB::from_int(255, 0, 0)
let blue = @color.RGB::from_int(0, 0, 255)

// Linear interpolation
let purple = @color.RGB::lerp(red, blue, 0.5)

// Generate gradient
let gradient = @color.RGB::gradient(red, blue, 10)
for i = 0; i < gradient.length(); i = i + 1 {
  println(gradient[i].to_hex())
}

// Multi-stop gradient
let rainbow = @color.RGB::multi_gradient([
  @color.RGB::from_hex("#FF0000"),
  @color.RGB::from_hex("#00FF00"),
  @color.RGB::from_hex("#0000FF")
], 20)

#WCAG Contrast Checking

let white = @color.RGB::from_int(255, 255, 255)
let black = @color.RGB::from_int(0, 0, 0)

// Calculate contrast ratio
let ratio = @color.RGB::contrast_ratio(white, black)
println("Contrast: " + ratio.to_string() + ":1")  // ~21:1

// Check WCAG compliance
if @color.RGB::meets_wcag_aa(white, black) {
  println("Passes WCAG AA (4.5:1)")
}

if @color.RGB::meets_wcag_aaa(white, black) {
  println("Passes WCAG AAA (7:1)")
}

#Palette Generation

let base = @color.RGB::from_int(255, 100, 50)

// Complementary color (opposite on color wheel)
let comp = base.complementary()

// Analogous palette (adjacent colors)
let analogous = base.analogous(5)

// Triadic palette (120° apart)
let triadic = base.triadic()

// Tetradic/square palette (90° apart)
let tetradic = base.tetradic()

// Monochromatic (same hue, varying lightness)
let mono = base.monochromatic(7)

// Split complementary
let split = base.split_complementary()

#API Reference

#RGB

#HSL / HSV

#Use Cases

• Data Visualization - Generate color scales for charts and graphs
• UI Design - Create harmonious color palettes
• Accessibility - Ensure sufficient contrast for readability
• Image Processing - Color space transformations
• Generative Art - Procedural color generation
• Theme Systems - Build adaptive color schemes

#Project Structure

moonbit-color/
├── color.mbt              # Core types & conversions
├── interpolation.mbt      # Color interpolation & gradients
├── contrast.mbt           # WCAG contrast calculations
├── palette.mbt            # Palette generation algorithms
├── color_test.mbt         # 18 unit tests
├── moon.mod.json          # Package metadata
├── moon.pkg.json          # Package config
└── README.md

#Testing

moon test    # Run 18 unit tests
moon check   # Type check
moon build   # Compile

• RGB/HSL/HSV conversions
• Hex parsing and formatting
• Color interpolation
• Gradient generation
• Luminance calculation
• Contrast ratio computation
• WCAG compliance checking
• All palette generation modes

#References

• W3C WCAG 2.1 Contrast Guidelines - https://www.w3.org/WAI/WCAG21/Understanding/contrast-minimum.html
• HSL/HSV conversion algorithms - https://en.wikipedia.org/wiki/HSL_and_HSV
• Color harmony theory - https://www.tigercolor.com/color-lab/color-theory/color-harmonies.htm

• chroma.js - https://gka.github.io/chroma.js/ (BSD-3-Clause)
• colord - https://github.com/omgovich/colord (MIT)

#License

#Author