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 NuGet.org, 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 or newer
• .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()
    .FromRGB(RGBWorkingSpaces.sRGB)
    .ToXYZ(Illuminants.D65)
    .Build();

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
    • J_zC_zh_z Delta-E_z
    • 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
    • PAL/SECAM 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*h°_ab (CIELCH)
  • Hunter Lab
• Luv color spaces
  • CIE L*u*v* (1976) (CIELUV)
  • CIE L*C*h°_uv (CIELCH)
• XYZ color space
  • CIE XYZ (1931)
  • CIE xyY (derived from XYZ)
• J_za_zb_z color spaces
  • J_za_zb_z (Safdar & al., 2017)
  • J_zC_zh_z (polar of J_za_zb_z)
• LMS color space
• xy chromaticity