Colormath

Colormath is a Kotlin Multiplatform library that allows you to convert between a number of color spaces, and to parse CSS colors into any of the supported color spaces.

Supported color spaces

• RGB
• CMYK
• HSL
• HSV
• XYZ
• LAB
• LUV
• ANSI-16 color codes
• ANSI-256 color codes

Most conversions run in a single step. If there isn't a formula for a direct conversion between two color spaces, the color will first be converted to another form such as RGB and then to final color space.

Usage

Conversion

Each color space is represented with a data class, and contains .toXXX() methods to convert to other spaces.

All color classes contain an alpha channel, which defaults to 1 (fully opaque) for color spaces that don't support transparency (such as ANSI color codes).

> RGB("#adcdef").toHSV()
HSV(h=211, s=28, v=94)

> RGB(r=12, g=128, b=255, a=.5f).toCMYK()
CMYK(c=95, m=50, y=0, k=0, a=.5f)

> HSL(180, 50, 50).toHex()
"#40bfbf"

CSS Parsing and rendering

You can parse any color allowed by the CSS Color Module Levels 1 through 4.

> Color.fromCss("#ff009980")
RGB(r=255, g=0, b=153, a=.5)

> Color.fromCss("rgb(100%, 0%, 60%)")
RGB(r=255, g=0, b=153, a=1)

> Color.fromCss("rgb(1e2, .5e1, .5e0, +.25e2%)")
RGB(r=100, g=5, b=1, a=.25)

> Color.fromCss("hsl(.75turn, 60%, 70%)")
HSL(h=270, s=60, l=70, a=1)

> Color.fromCss("rebeccapurple").toHex()
"#663399"

You can also render any color in CSS rgb or hsl functional or whitespace notation

> RGB(255, 0, 128).toCssRgb()
"rgb(255, 0, 128)"

> RGB(255, 0, 128, .5f).toCssRgb(rgbStyle=PERCENT)
"rgb(100%, 0%, 50%, .5)"

> XYZ(25.0, 50.0, 75.0, .5f).toCssHsl(commas = false, hueUnit = RADIANS)
"hsl(3.1241rad 100% 44% / .5)"

Installation

Colormath is distributed through Maven Central.

dependencies {
   implementation("com.github.ajalt.colormath:colormath:2.0.0")
}

In version 2.0, the maven coordinates changed. Make sure you're using the new coordinates if you're updating from an older version.

Multiplatform

Colormath supports the following targets: jvm, mingwX64, linuxX64, macosX64, ios, watchos, tvos, and js (for both NodeJS and Browsers). You'll need to use Gradle 6 or newer.

Snapshots

repositories {
    maven {
        url = uri("https://oss.sonatype.org/content/repositories/snapshots/")
    }
}

License

Copyright 2018-2020 AJ Alt

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.