Construction and Conversion

Available colorspaces

The colorspaces used by Colors are defined in ColorTypes. Briefly, the defined spaces are:

• Red-Green-Blue spaces: RGB, BGR, XRGB, RGBX, RGB24, plus transparent versions ARGB, RGBA, ABGR, BGRA, and ARGB32.

• HSV, HSL, HSI, plus all 6 transparent variants (AHSV, HSVA, AHSL, HSLA, AHSI, HSIA)

• XYZ, xyY, LMS and all 6 transparent variants

• Lab, Luv, LCHab, LCHuv and all 8 transparent variants

• Oklab, Oklch and their transparent variants

• DIN99, DIN99d, DIN99o and all 6 transparent variants

• Storage formats YIQ, YCbCr and their transparent variants

• Gray, Gray24, and the transparent variants AGray, GrayA, and AGray32.

Color Parsing

You can parse any CSS color specification with the exception of currentColor. You can construct colors from strings using the @colorant_str macro and the parse function.

julia> using Colors

julia> colorant"red" # named color
RGB{N0f8}(1.0, 0.0, 0.0)

julia> parse(Colorant, "DeepSkyBlue") # color names are case-insensitive
RGB{N0f8}(0.0, 0.749, 1.0)

julia> colorant"#FF0000" # 6-digit hex notation
RGB{N0f8}(1.0, 0.0, 0.0)

julia> colorant"#f00" # 3-digit hex notation
RGB{N0f8}(1.0, 0.0, 0.0)

julia> colorant"rgb(255,0,0)" # rgb() notation with integers in [0, 255]
RGB{N0f8}(1.0, 0.0, 0.0)

julia> colorant"rgba(255,0,0,0.6)" # with alpha in [0, 1]
RGBA{N0f8}(1.0, 0.0, 0.0, 0.6)

julia> colorant"rgba(100%,80%,0.0%,0.6)" # with percentages
RGBA{N0f8}(1.0, 0.8, 0.0, 0.6)

julia> parse(ARGB, "rgba(255,0,0,0.6)") # you can specify the return type
ARGB{N0f8}(1.0, 0.0, 0.0, 0.6)

julia> colorant"hsl(120, 100%, 25%)" # hsl() notation
HSL{Float32}(120.0, 1.0, 0.25)

julia> colorant"hsla(120, 100%, 25%, 60%)" # hsla() notation
HSLA{Float32}(120.0, 1.0, 0.25, 0.6)

julia> colorant"transparent" # transparent "black"
RGBA{N0f8}(0.0, 0.0, 0.0, 0.0)

All CSS/SVG named colors are supported, in addition to X11 named colors, when their definitions do not clash with SVG. You can find all names and their color swatches in Named Colors page.

When writing functions the colorant"red" version is preferred, because the slow step runs when the code is parsed (i.e., during compilation rather than run-time).

The element types of the return types depend on the colorspaces, i.e. the hsl() and hsla() notations return HSL/HSLA colors with Float32 elements, and other notations return RGB/RGBA colors with N0f8 elements. The result colors can be converted to RGB{N0f16} (for example) using:

julia> using FixedPointNumbers

julia> RGB{N0f16}(colorant"indianred")
RGB{N0f16}(0.80392, 0.36078, 0.36078)

or

julia> parse(RGB{N0f16}, "indianred")
RGB{N0f16}(0.80392, 0.36078, 0.36078)

You can convert colors to hexadecimal strings using the hex function. Note that the conversion result does not have the prefix "#".

julia> col = colorant"#C0FFEE"
RGB{N0f8}(0.753, 1.0, 0.933)

julia> hex(col)
"C0FFEE"

Color Conversions

Colors.jl allows you to convert from one colorspace to another using the convert function.

For example:

julia> convert(RGB, HSL(270, 0.5, 0.5)) # without the element type
RGB{Float64}(0.5, 0.25, 0.75)

julia> convert(RGB{N0f8}, HSL(270, 0.5, 0.5)) # with the element type
RGB{N0f8}(0.502, 0.251, 0.749)

Depending on the source and destination colorspace, this may not be perfectly lossless.

Transparent - Opaque Conversions

Colors.jl allows you to convert colors to transparent or opaque types.

julia> col = colorant"yellow"
RGB{N0f8}(1.0, 1.0, 0.0)

julia> transparent = alphacolor(col, 0.5)  # or coloralpha(col)
ARGB{N0f8}(1.0, 1.0, 0.0, 0.502)

julia> opaque = color(transparent)
RGB{N0f8}(1.0, 1.0, 0.0)

@colorant_str(ex)

parse(Colorant, desc)

julia> parse(Colorant, "#FF8800AA") # transparent orange
RGBA{N0f8}(1.0,0.533,0.0,0.667)

julia> parse(Colorant, "0xFF8800AA") # opaque purple
ARGB{N0f8}(0.533,0.0,0.667,1.0)

hex(c::Colorant)
hex(c::Colorant, style::Symbol)

julia> hex(RGB(1,0.5,0))
"FF8000"

julia> hex(ARGB(1,0.5,0,0.25))
"40FF8000"

julia> hex(HSV(30,1.0,1.0), :AARRGGBB)
"FFFF8000"

julia> hex(ARGB(1,0.533,0,0.267), :rrggbbaa)
"ff880044"

julia> hex(ARGB(1,0.533,0,0.267), :rgba)
"f804"

julia> hex(ARGB(1,0.533,0,0.267), :S)
"4F80"

normalize_hue(h::Real)
normalize_hue(c::Colorant)

mean_hue(h1::Real, h2::Real)
mean_hue(a::C, b::C) where {C <: Colorant}