Noire 
A color library which supports converting between the RGB, HSL, HSV, CMYK, Hex, HTML and some additional functions (tint, saturation).
Requires atleast Go 1.10 version due to the math.Round(https://golang.org/pkg/math/#Round) function call.
Supported colors
Noire is able to convert the colors between:
- RGB
- CMYK
- HSL
- HSV
- Hex
- HTML
Benchmark
Specification:
4.2 GHz Intel Core i7 (8750H)
32 GB 2666 MHz DDR4
goos: windows
goarch: amd64
pkg: github.com/teacat/noire
BenchmarkCMYKToRGB-12 100000000 22.5 ns/op 0 B/op 0 allocs/op
BenchmarkRGBToCMYK-12 50000000 26.9 ns/op 0 B/op 0 allocs/op
BenchmarkRGBToHSL-12 50000000 26.6 ns/op 0 B/op 0 allocs/op
BenchmarkHSLToRGB-12 100000000 17.2 ns/op 0 B/op 0 allocs/op
BenchmarkHSVToRGB-12 100000000 15.3 ns/op 0 B/op 0 allocs/op
BenchmarkRGBToHSV-12 50000000 29.3 ns/op 0 B/op 0 allocs/op
BenchmarkRGBToHex-12 20000000 85.4 ns/op 32 B/op 4 allocs/op
BenchmarkHexToRGB-12 50000000 36.1 ns/op 8 B/op 1 allocs/op
BenchmarkHTMLToRGBName-12 20000000 118 ns/op 40 B/op 3 allocs/op
BenchmarkHTMLToRGBHex-12 30000000 41.0 ns/op 8 B/op 1 allocs/op
BenchmarkRGBToHTML-12 20000000 103 ns/op 32 B/op 4 allocs/op
BenchmarkMix-12 5000000 292 ns/op 112 B/op 5 allocs/op
BenchmarkHue-12 50000000 33.5 ns/op 0 B/op 0 allocs/op
BenchmarkSaturation-12 50000000 33.7 ns/op 0 B/op 0 allocs/op
BenchmarkLightness-12 50000000 33.7 ns/op 0 B/op 0 allocs/op
BenchmarkAdjustHue-12 20000000 79.0 ns/op 32 B/op 1 allocs/op
BenchmarkLighten-12 20000000 78.2 ns/op 32 B/op 1 allocs/op
BenchmarkDarken-12 20000000 77.8 ns/op 32 B/op 1 allocs/op
BenchmarkSaturate-12 20000000 74.1 ns/op 32 B/op 1 allocs/op
BenchmarkDesaturate-12 20000000 79.0 ns/op 32 B/op 1 allocs/op
BenchmarkGrayscale-12 20000000 71.8 ns/op 32 B/op 1 allocs/op
BenchmarkComplement-12 20000000 79.9 ns/op 32 B/op 1 allocs/op
BenchmarkTint-12 30000000 40.8 ns/op 32 B/op 1 allocs/op
BenchmarkShade-12 30000000 40.9 ns/op 32 B/op 1 allocs/op
BenchmarkInvert-12 50000000 24.9 ns/op 32 B/op 1 allocs/op
BenchmarkLuminanaceWCAG-12 10000000 224 ns/op 0 B/op 0 allocs/op
BenchmarkLuminanace-12 300000000 6.00 ns/op 0 B/op 0 allocs/op
BenchmarkContrast-12 5000000 257 ns/op 0 B/op 0 allocs/op
BenchmarkIsLight-12 2000000000 0.26 ns/op 0 B/op 0 allocs/op
BenchmarkIsDark-12 2000000000 0.26 ns/op 0 B/op 0 allocs/op
BenchmarkHSV-12 50000000 34.2 ns/op 0 B/op 0 allocs/op
BenchmarkHSVA-12 50000000 35.0 ns/op 0 B/op 0 allocs/op
BenchmarkHSL-12 50000000 31.9 ns/op 0 B/op 0 allocs/op
BenchmarkHSLA-12 50000000 32.0 ns/op 0 B/op 0 allocs/op
BenchmarkRGB-12 2000000000 0.52 ns/op 0 B/op 0 allocs/op
BenchmarkRGBA-12 2000000000 0.26 ns/op 0 B/op 0 allocs/op
BenchmarkCMYK-12 50000000 32.9 ns/op 0 B/op 0 allocs/op
BenchmarkHex-12 20000000 90.1 ns/op 32 B/op 4 allocs/op
BenchmarkHTMLHex-12 10000000 146 ns/op 40 B/op 5 allocs/op
BenchmarkHTMLName-12 20000000 107 ns/op 32 B/op 4 allocs/op
BenchmarkHTMLRGBA-12 2000000 839 ns/op 96 B/op 5 allocs/op
PASS
ok github.com/teacat/noire 67.640s
Success: Benchmarks passed.
Installation
To install Noire by simply typing go get in the terminal.
$ go get github.com/teacat/noireUsage
Initialize a new color with noire.NewRGB (or NewHex) to modify the color with Lighten or Tint, etc.
package main
import (
"fmt"
"github.com/teacat/noire"
)
func main() {
c := noire.NewRGB(255, 255, 255)
fmt.Println(c.Invert().Hex()) // Output: 000000
fmt.Println(c.Invert().HTML()) // Output: Black
fmt.Println(c.Lighten(1).RGB()) // Output: 255, 255, 255
}Description
There are few functions results cannot be visualized, so make sure to check the GoDoc to see how they work.
Hue: Get the Hue angle of the current color based on the HSL algorithm.Saturation: Get the Saturation of the current color based on the HSL algorithm.Lightness： Get the Lightness of the current color based on the HSL algorithm.LuminanaceWCAG：Get the Luminance of the current color based on the WCAG 2.0 algorithm.Luminanace: Get the Luminance of the current color.Contrast: Get the Contrast of the current color based on the WCAG Luminance algorithm.IsLight: Returns true if the color is a light scheme, it might not be the same as what human eyes can see.IsDark: Returns true if the color is a dark scheme, it might not be the same as what human eyes can see.
Lighten
Lighten a color based on HSL mode, it might makes the color a bit way too bright or washed out.
func main() {
c := NewRGB(219, 112, 148)
fmt.Println(c.Lighten(0.15).Hex()) // Output: EAADC2
}Brighten
Increases the brightness of the color based on RGB mode.
func main() {
c := NewRGB(0, 0, 0)
fmt.Println(c.Brighten(0.1).Hex()) // Output: 1A1A1A
}Tint
Mixing with a white color as base to get the best balance to increase the brightness of a color.
func main() {
c := NewRGB(0, 0, 0)
fmt.Println(c.Tint(0.1).Hex()) // Output: 1A1A1A
}Darken
Darken a color based on HSL mode, it might makes the color a bit way too dark or dimmed.
func main() {
c := NewRGB(219, 112, 148)
fmt.Println(c.Darken(0.15).Hex()) // Output: CB3366
}Shade
Mixing with a black color as base to get the best balance to increase the brightness of a color.
func main() {
c := NewRGB(219, 112, 148)
fmt.Println(c.Shade(0.15).Hex()) // Output: BA5F7E
}Saturate
Increases the saturation of the color based on HSL mode.
func main() {
c := NewRGB(219, 112, 148)
fmt.Println(c.Saturate(0.5).Hex()) // Output: FF4C88
}Desaturate
Decreases the saturation of the color based on HSL mode.
func main() {
c := NewRGB(219, 112, 148)
fmt.Println(c.Desaturate(0.15).Hex()) // Output: AE9DA3
}AdjustHue
Rotates the Hue angle of the color based on HSL mode, it still goes clockwise if the value was set over than 360 degree.
func main() {
c := NewRGB(219, 112, 148)
fmt.Println(c.AdjustHue(30).Hex()) // Output: DB8270
}Mix
Mixing two colors with a value that specified the weight of the second color.
func main() {
c1 := NewHex("F00")
c2 := NewHex("00F")
fmt.Println(c1.Mix(c2, 0.5).HTML()) // Output: Purple
}Invert
Get the opposite color that based on the RGB color map (it's not a complementary color).
func main() {
c := NewRGB(219, 112, 148)
fmt.Println(c.Invert().Hex()) // Output: 248F6B
}Complement
Get the complementary color of the current color, same as AdjustHue(180).
func main() {
c := NewRGB(219, 112, 148)
fmt.Println(c.Complement().Hex()) // Output: 70DBB7
}Grayscale
Converts the color to grayscale, same as Desaturate(1).
func main() {
c := NewRGB(219, 112, 148)
fmt.Println(c.Grayscale().Hex()) // Output: A5A5A5
}Foreground
Get the suggested foreground color by calculating the color luminance, it returns a white color when the color is dark, vise versa.
func main() {
c := NewHTML("Green")
fmt.Println(c.Foreground().HTML()) // Output: White
c = NewHTML("Red")
fmt.Println(c.Foreground().HTML()) // Output: White
c = NewHTML("Yellow")
fmt.Println(c.Foreground().HTML()) // Output: Black
}References
RGB 轉 HSV, HSL (線上色碼轉換 HSL, HSV, RGB, HEX)
ozdemirburak/iris: PHP library for color manipulation and conversion.
Using Sass to automatically pick text colors
Relative luminance - Wikipedia
image - Formula to determine brightness of RGB color - Stack Overflow