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Colourful logo Colourful .NET

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Open source .NET library for working with color spaces.

The library is written in C# and released with an MIT license, so feel free to fork or use commercially.

Any feedback is appreciated, please visit the issues page or send me an e-mail.


Binaries of the last build can be downloaded on the AppVeyor CI page of the project.

The library is also published on, install using:

PM> Install-Package Colourful

Colourful is CLS Compliant (to allow use in VB.NET etc.) and is built for these target frameworks:

  • .NET 6
  • .NET Framework 4.5
  • .NET Standard 2.0
  • .NET Standard 1.1
  • For older .NET Framework 4.0 see version 1 of the library.


Example "hello world" usage that converts a color from sRGB to XYZ (keeping the D65 white point):

IColorConverter<RGBColor, XYZColor> converter = new ConverterBuilder()

RGBColor rgbColor = new RGBColor(1, 0, 0.5);
XYZColor xyzColor = converter.Convert(rgbColor); // XYZ [X=0.45, Y=0.23, Z=0.22]


Please see the docs pages below for various topics:

  • Conversion between color spaces
    • also handles chromatic adaptation with multiple possible LMS transformation matrices:
      • Bradford (default)
      • Von Kries (Hunt-Pointer-Estevez adjusted for D65)
      • Von Kries (Hunt-Pointer-Estevez for equal energy)
      • XYZ scaling
      • Spectral-sharpened Bradford
      • CMCCAT2000
      • CAT02
      • (user-defined chromatic adaptation matrix)
  • Correlated color temperature (CCT)
    • Planckian locus approximation method
  • Ranges of channel values and clamping
  • Computing color difference
    • multiple algorithms supported:
      • CIE Delta-E 1976
      • CMC l:c (1984)
      • CIE Delta-E 1994
      • CIE Delta-E 2000
      • JzCzhz Delta-Ez
      • Euclidean distance
  • Cylindrical color spaces
  • Illuminants and white points
    • white points are handled correctly throughout the conversions
    • multiple illuminant are built-in:
      • A (Incandescent / Tungsten)
      • B (Direct sunlight at noon (obsolete))
      • C (Average / North sky Daylight (obsolete))
      • D50 (Horizon Light. ICC profile PCS)
      • D55 (Mid-morning / Mid-afternoon Daylight)
      • D65 (Noon Daylight: Television, sRGB color space)
      • D75 (North sky Daylight)
      • E (Equal energy)
      • F2 (Cool White Fluorescent)
      • F7 (D65 simulator, Daylight simulator)
      • F11 (Philips TL84, Ultralume 40)
      • (user-defined white points)
  • Macbeth ColorChecker chart
  • Changes between v2 and v3

For information about specific color spaces, see the following docs pages:

  • RGB color spaces
    • support for both ordinary RGB and linear RGB
    • multiple working spaces supported:
      • sRGB
      • Simplified sRGB
      • ECI RGB v2
      • Adobe RGB (1998)
      • Apple sRGB
      • Best RGB
      • Beta RGB
      • Bruce RGB
      • CIE RGB
      • ColorMatch RGB
      • Don RGB 4
      • Ekta Space PS5
      • NTSC RGB
      • ProPhoto RGB
      • SMPTE-C RGB
      • Wide Gamut RGB
      • Rec. 709 (ITU-R Recommendation BT.709 – HDTV)
      • Rec. 2020 (ITU-R Recommendation BT.2020 – UHDTV)
      • (user-defined RGB working spaces)
  • Lab color spaces
    • CIE L*a*b* (1976) (CIELAB)
    • CIE L*C*hΒ°ab (CIELCH)
    • Hunter Lab
  • Luv color spaces
    • CIE L*u*v* (1976) (CIELUV)
    • CIE L*C*hΒ°uv (CIELCH)
  • XYZ color space
    • CIE XYZ (1931)
    • CIE xyY (derived from XYZ)
  • Jzazbz color spaces
    • Jzazbz (Safdar & al., 2017)
    • JzCzhz (polar of Jzazbz)
  • LMS color space
  • xy chromaticity