Colormath is a Kotlin Multiplatform library for color manipulation and conversion.

Colormath can:

• Convert between color models and spaces
• Manipulate colors with transformations such as mixing and chromatic adaptation
• Calculate attributes such as WCAG contrast and perceptual color difference
• Generate gradients with custom interpolation methods and easing functions
• Parse and render colors as strings, including all representations from the CSS spec

// Create an sRGB color
val color = RGB("#ff23cc")

// Interpolate with another color
val mixed = color.interpolate(RGB(0.1, 0.4, 1), 0.5f)
// RGB("#8c45e6")

// Convert to a different color space
val lab = mixed.toLAB()
// LAB(46.3, 60.9, -70)

// Change the transparency
val labA = lab.copy(alpha = 0.25f)
// LAB(46.3, 60.9, -70, 0.25)

// Adapt white point
val lab50 = labA.convertTo(LAB50)
// LAB50(45, 55.1812, 72.5911, 0.25)

// Render as a css color string
println(lab50.formatCssString())
// "lab(45% 55.1812 -72.5911 / 0.25)"

The full documentation can be found on the website.

There are also some online examples:

• Color space converter
• Gradient generator

Installation

Colormath is distributed through Maven Central.

dependencies {
    implementation("com.github.ajalt.colormath:colormath:3.4.0")

    // optional extensions for interop with other platforms
    //
    // android.graphics.Color
    implementation("com.github.ajalt.colormath:colormath-ext-android-color:3.4.0")
    // androidx.annotation.ColorInt
    implementation("com.github.ajalt.colormath:colormath-ext-android-colorint:3.4.0")
    // androidx.compose.ui.graphics.Color
    implementation("com.github.ajalt.colormath:colormath-ext-jetpack-compose:3.4.0")
}

If you're using Maven instead of Gradle, use <artifactId>colormath-jvm</artifactId>

Multiplatform

Colormath publishes artifacts for all Tier 1 and Tier 2 targets, as well as mingwX64 and wasm.

wasm and the arm64 targets are not tested on CI.

Snapshots

Snapshot builds are also available

You'll need to add the Sonatype snapshots repository: kotlin repositories { maven { url = uri("https://oss.sonatype.org/content/repositories/snapshots/") } }