Prism 🌈 #

A high-performance color manipulation library for Dart & Flutter with multiple color models, accessibility-focused schemes, and pre-built palettes.

See prism_flutter which adds Flutter specific extensions.

Resources #

• Repository on GitHub
• Package on Pub.dev
• Documentation
• Flutter package

Features #

• 🎨 Multiple color models: RGB (8-bit & 16-bit), HSL, Oklab, and Oklch with seamless conversion
• 🎭 Accessibility schemes: WCAG-compliant color schemes with optimal contrast
• 🎨 Pre-built palettes: Material, CSS, Spectrum, and OpenColor palettes
• 📱 Flutter compatible: Perfect conversion to/from Flutter's Color class
• ⚡ High performance: Zero dependencies with optimized bit operations
• 🌐 Web standards: RGBA/ARGB hex format support

Quick Start #

import 'package:prism/prism.dart';

// Create and convert colors
final red = RayRgb8.fromHex('#FF0000');
final redInOklch = red.toOklch();                 // Convert to perceptual color space
final darkRed = redInOklch.withLightness(0.3);    // Darken perceptually 
print(darkRed.toRgb8().toHexStr());               // #521711

// Generate accessibility schemes
final scheme = RayScheme.fromRay(red);
final darkSurface = scheme.surfaceDark;           // Dark theme surface
final textColor = darkSurface.onRay;              // Optimal contrast color

Color Models #

Prism supports multiple color models with seamless conversion:

RayRgb8 & RayRgb16 (Red, Green, Blue) #

final red8 = RayRgb8.fromHex('#FF0000');                 // 8-bit channels (0-255)
final red16 = RayRgb16.fromHex('#FF0000');               // 16-bit channels (0-65535)
final transparent = red8.withOpacity(0.5);               // With transparency
final webHex = red8.toHexStr();                          // Web standard: #FF0000
final flutterHex = red8.toHexStr(format: HexFormat.argb); // Flutter: #FFFF0000

RayHsl (Hue, Saturation, Lightness) #

final orange = RayHsl(hue: 30, saturation: 0.8, lightness: 0.6);
final green = RayHsl(hue: 120, saturation: 0.5, lightness: 0.4);
final shifted = orange.withHue(orange.hue + 60);      // Hue shift
print('Hue distance: ${orange.hueDistance(green)}°'); // Color analysis: 90.0°

RayOklab (Perceptually Uniform Color Space) #

final rgbBlue = RayRgb8.fromHex('#0000FF').toOklab(); // Convert from RGB
final rgbRed = RayRgb8.fromHex('#FF0000').toOklab();  // Convert from RGB
final midpoint = rgbBlue.lerp(rgbRed, 0.5);            // Perceptually uniform interpolation

RayOklch (Cylindrical Oklab with Intuitive Controls) #

final baseColor = RayOklch(l: 0.7, c: 0.15, h: 120.0);      // Lightness, Chroma, Hue
final desaturated = baseColor.withChroma(0.05);             // Reduce saturation
final complementary = baseColor.withHue(baseColor.h + 180); // Complementary color

Seamless Conversion #

final rgbRed = RayRgb8.fromHex('#FF0000');
final hslRed = rgbRed.toHsl();              // RGB → HSL
final oklchRed = rgbRed.toOklch();          // RGB → Oklch  
final backToRgb = hslRed.toRgb8();          // HSL → RGB

Performance #

Optimized for performance with efficient bit operations, minimal allocations, and zero dependencies.

Color Palettes #

Prism includes extensive pre-built color palettes with accessibility-focused schemes:

Available Palettes #

Spectrum (Prim's own color palette)

Material Colors

Open Color

CSS Colors

CSS versions of all palettes are also available in the palette_gallery/ directory for web development use.

Usage #

import 'package:prism/palettes/rgb/spectrum.dart';
final primaryBlue = SpectrumRgb.blue.source;
final darkBlue = SpectrumRgb.blue.shade700;

License #

MIT License © 2025 Jimmy Forrester-Fellowes - see LICENSE file for details.

For an introduction to Prsim see Jimmy's blog post.