Module

CSS.Color

Package: purescript-css
Repository: purescript-contrib/purescript-css

Re-exports from Color

#ColorSpace

data ColorSpace

Definition of a color space.

RGB: red, green, blue
HSL: hue, saturation, lightness
LCh: Lightness, chroma, hue
Lab: Lightness, a, b

Constructors

RGB
HSL
LCh
Lab

#Color

data Color

The representation of a color.

Note:

The Eq instance compares two Colors by comparing their (integer) RGB values. This is different from comparing the HSL values (for example, HSL has many different representations of black (arbitrary hue and saturation values).
Colors outside the sRGB gamut which cannot be displayed on a typical computer screen can not be represented by Color.

Instances

Show Color
Eq Color

#xyz

xyz :: Number -> Number -> Number -> Color

Create a Color from XYZ coordinates in the CIE 1931 color space. Note that a Color always represents a color in the sRGB gamut (colors that can be represented on a typical computer screen) while the XYZ color space is bigger. This function will tend to create fully saturated colors at the edge of the sRGB gamut if the coordinates lie outside the sRGB range.

See:

#white

white :: Color

Pure white.

#toXYZ

toXYZ :: Color -> { x :: Number, y :: Number, z :: Number }

Get XYZ coordinates according to the CIE 1931 color space.

See:

#toRGBA'

toRGBA' :: Color -> { a :: Number, b :: Number, g :: Number, r :: Number }

Convert a Color to its red, green, blue and alpha values. All values are numbers in the range from 0.0 to 1.0.

#toRGBA

toRGBA :: Color -> { a :: Number, b :: Int, g :: Int, r :: Int }

Convert a Color to its red, green, blue and alpha values. The RGB values are integers in the range from 0 to 255. The alpha channel is a number between 0.0 and 1.0.

#toLab

toLab :: Color -> { a :: Number, b :: Number, l :: Number }

Get L, a and b coordinates according to the Lab color space.

See: https://en.wikipedia.org/wiki/Lab_color_space

#toLCh

toLCh :: Color -> { c :: Number, h :: Number, l :: Number }

Get L, C and h coordinates according to the CIE LCh color space.

See: https://en.wikipedia.org/wiki/Lab_color_space

#toHexString

toHexString :: Color -> String

Return a hexadecimal representation of the color in the form #rrggbb, where rr, gg and bb refer to hexadecimal digits corresponding to the RGB channel values between 00 and ff. The alpha channel is not represented.

#toHSLA

toHSLA :: Color -> { a :: Number, h :: Number, l :: Number, s :: Number }

Convert a Color to its Hue, Saturation, Lightness and Alpha values. See hsla for the ranges of each channel.

#toGray

toGray :: Color -> Color

Convert a color to a gray tone with the same perceived luminance (see luminance).

#textColor

textColor :: Color -> Color

Return a readable foreground text color (either black or white) for a given background color.

#saturate

saturate :: Number -> Color -> Color

Increase the saturation of a color by adding a certain amount (number between -1.0 and 1.0) to the saturation channel. If the number is negative, the color is desaturated.

#rotateHue

rotateHue :: Number -> Color -> Color

Rotate the hue of a Color by a certain angle (in degrees).

#rgba'

rgba' :: Number -> Number -> Number -> Number -> Color

Create a Color from RGB and alpha values between 0.0 and 1.0.

#rgba

rgba :: Int -> Int -> Int -> Number -> Color

Create a Color from integer RGB values between 0 and 255 and a floating point alpha value between 0.0 and 1.0.

#rgb'

rgb' :: Number -> Number -> Number -> Color

Create a Color from RGB values between 0.0 and 1.0.

#rgb

rgb :: Int -> Int -> Int -> Color

Create a Color from integer RGB values between 0 and 255.

#mix

mix :: ColorSpace -> Interpolator

Mix two colors by linearly interpolating between them in the specified color space. For the HSL colorspace, the shortest path is chosen along the circle of hue values.

#luminance

luminance :: Color -> Number

The relative brightness of a color (normalized to 0.0 for darkest black and 1.0 for lightest white), according to the WCAG definition.

See: https://www.w3.org/TR/2008/REC-WCAG20-20081211/#relativeluminancedef

#lighten

lighten :: Number -> Color -> Color

Lighten a color by adding a certain amount (number between -1.0 and 1.0) to the lightness channel. If the number is negative, the color is darkened.

#lch

lch :: Number -> Number -> Number -> Color

Create a Color from lightness, chroma and hue coordinates in the CIE LCh color space. This is a cylindrical transform of the Lab color space. Note: See documentation for xyz. The same restrictions apply here.

See: https://en.wikipedia.org/wiki/Lab_color_space

#lab

lab :: Number -> Number -> Number -> Color

Create a Color from L, a and b coordinates coordinates in the Lab color space. Note: See documentation for xyz. The same restrictions apply here.

See: https://en.wikipedia.org/wiki/Lab_color_space

#isReadable

isReadable :: Color -> Color -> Boolean

Determine whether text of one color is readable on a background of a different color (see contrast). This function is symmetric in both arguments.

isReadable c1 c2 = contrast c1 c2 > 4.5

#isLight

isLight :: Color -> Boolean

Determine whether a color is perceived as a light color.

isLight c = brightness c > 0.5

#hsla

hsla :: Number -> Number -> Number -> Number -> Color

Create a Color from Hue, Saturation, Lightness and Alpha values. The Hue is given in degrees, as a Number between 0.0 and 360.0. Saturation, Lightness and Alpha are numbers between 0.0 and 1.0.

#hsl

hsl :: Number -> Number -> Number -> Color

Create a Color from Hue, Saturation and Lightness values. The Hue is given in degrees, as a Number between 0.0 and 360.0. Both Saturation and Lightness are numbers between 0.0 and 1.0.

#graytone

graytone :: Number -> Color

Create a gray tone from a lightness values (0.0 is black, 1.0 is white).

#fromInt

fromInt :: Int -> Color

Converts an integer to a color (RGB representation). 0 is black and 0xffffff is white. Values outside this range will be clamped.

This function is useful if you want to hard-code Hex values. For example:

red = fromInt 0xff0000

#fromHexString

fromHexString :: String -> Maybe Color

Parse a hexadecimal RGB code of the form #rgb or #rrggbb. The # character is required. Each hexadecimal digit is of the form [0-9a-fA-F] (case insensitive). Returns Nothing if the string is in a wrong format.

#distance

distance :: Color -> Color -> Number

Compute the perceived 'distance' between two colors according to the CIE76 delta-E standard. A distance below ~2.3 is not noticable.

See: https://en.wikipedia.org/wiki/Color_difference

#desaturate

desaturate :: Number -> Color -> Color

Decrease the saturation of a color by subtracting a certain amount (number between -1.0 and 1.0) from the saturation channel. If the number is negative, the color is saturated.

#darken

darken :: Number -> Color -> Color

Darken a color by subtracting a certain amount (number between -1.0 and 1.0) from the lightness channel. If the number is negative, the color is lightened.

#cssStringRGBA

cssStringRGBA :: Color -> String

A CSS representation of the color in the form rgb(..) or rgba(...).

#cssStringHSLA

cssStringHSLA :: Color -> String

A CSS representation of the color in the form hsl(..) or hsla(...).

#contrast

contrast :: Color -> Color -> Number

The contrast ratio of two colors. A minimum contrast ratio of 4.5 is recommended to ensure that text is readable on a colored background. The contrast ratio is symmetric on both arguments: contrast c1 c2 == contrast c2 c1.

See http://www.w3.org/TR/2008/REC-WCAG20-20081211/#contrast-ratiodef

#complementary

complementary :: Color -> Color

Get the complementary color (hue rotated by 180°).

#brightness

brightness :: Color -> Number

The percieved brightness of the color (A number between 0.0 and 1.0).

See: https://www.w3.org/TR/AERT#color-contrast

#black

black :: Color

Pure black.

Re-exports from Color.Scheme.X11

#yellowgreen

yellowgreen :: Color

#yellow

yellow :: Color

#whitesmoke

whitesmoke :: Color

#wheat

wheat :: Color

#violet

violet :: Color

#turquoise

turquoise :: Color

#tomato

tomato :: Color

#thistle

thistle :: Color

#teal

teal :: Color

#tan

tan :: Color

#steelblue

steelblue :: Color

#springgreen

springgreen :: Color

#snow

snow :: Color

#slategrey

slategrey :: Color

#slategray

slategray :: Color

#slateblue

slateblue :: Color

#skyblue

skyblue :: Color

#silver

silver :: Color

#sienna

sienna :: Color

#seashell

seashell :: Color

#seagreen

seagreen :: Color

#sandybrown

sandybrown :: Color

#salmon

salmon :: Color

#saddlebrown

saddlebrown :: Color

#royalblue

royalblue :: Color

#rosybrown

rosybrown :: Color

#red

red :: Color

#purple

purple :: Color

#powderblue

powderblue :: Color

#plum

plum :: Color

#pink

pink :: Color

#peru

peru :: Color

#peachpuff

peachpuff :: Color

#papayawhip

papayawhip :: Color

#palevioletred

palevioletred :: Color

#paleturquoise

paleturquoise :: Color

#palegreen

palegreen :: Color

#palegoldenrod

palegoldenrod :: Color

#orchid

orchid :: Color

#orangered

orangered :: Color

#orange

orange :: Color

#olivedrab

olivedrab :: Color

#olive

olive :: Color

#oldlace

oldlace :: Color

#navy

navy :: Color

#navajowhite

navajowhite :: Color

#moccasin

moccasin :: Color

#mistyrose

mistyrose :: Color

#mintcream

mintcream :: Color

#midnightblue

midnightblue :: Color

#mediumvioletred

mediumvioletred :: Color

#mediumturquoise

mediumturquoise :: Color

#mediumspringgreen

mediumspringgreen :: Color

#mediumslateblue

mediumslateblue :: Color

#mediumseagreen

mediumseagreen :: Color

#mediumpurple

mediumpurple :: Color

#mediumorchid

mediumorchid :: Color

#mediumblue

mediumblue :: Color

#mediumaquamarine

mediumaquamarine :: Color

#maroon

maroon :: Color

#magenta

magenta :: Color

#linen

linen :: Color

#limegreen

limegreen :: Color

#lime

lime :: Color

#lightyellow

lightyellow :: Color

#lightsteelblue

lightsteelblue :: Color

#lightslategrey

lightslategrey :: Color

#lightslategray

lightslategray :: Color

#lightskyblue

lightskyblue :: Color

#lightseagreen

lightseagreen :: Color

#lightsalmon

lightsalmon :: Color

#lightpink

lightpink :: Color

#lightgrey

lightgrey :: Color

#lightgreen

lightgreen :: Color

#lightgray

lightgray :: Color

#lightgoldenrodyellow

lightgoldenrodyellow :: Color

#lightcyan

lightcyan :: Color

#lightcoral

lightcoral :: Color

#lightblue

lightblue :: Color

#lemonchiffon

lemonchiffon :: Color

#lawngreen

lawngreen :: Color

#lavenderblush

lavenderblush :: Color

#lavender

lavender :: Color

#khaki

khaki :: Color

#ivory

ivory :: Color

#indigo

indigo :: Color

#indianred

indianred :: Color

#hotpink

hotpink :: Color

#honeydew

honeydew :: Color

#grey

grey :: Color

#greenyellow

greenyellow :: Color

#green

green :: Color

#gray

gray :: Color

#goldenrod

goldenrod :: Color

#gold

gold :: Color

#ghostwhite

ghostwhite :: Color

#gainsboro

gainsboro :: Color

#fuchsia

fuchsia :: Color

#forestgreen

forestgreen :: Color

#floralwhite

floralwhite :: Color

#firebrick

firebrick :: Color

#dodgerblue

dodgerblue :: Color

#dimgrey

dimgrey :: Color

#dimgray

dimgray :: Color

#deepskyblue

deepskyblue :: Color

#deeppink

deeppink :: Color

#darkviolet

darkviolet :: Color

#darkturquoise

darkturquoise :: Color

#darkslategrey

darkslategrey :: Color

#darkslategray

darkslategray :: Color

#darkslateblue

darkslateblue :: Color

#darkseagreen

darkseagreen :: Color

#darksalmon

darksalmon :: Color

#darkred

darkred :: Color

#darkorchid

darkorchid :: Color

#darkorange

darkorange :: Color

#darkolivegreen

darkolivegreen :: Color

#darkmagenta

darkmagenta :: Color

#darkkhaki

darkkhaki :: Color

#darkgrey

darkgrey :: Color

#darkgreen

darkgreen :: Color

#darkgray

darkgray :: Color

#darkgoldenrod

darkgoldenrod :: Color

#darkcyan

darkcyan :: Color

#darkblue

darkblue :: Color

#cyan

cyan :: Color

#crimson

crimson :: Color

#cornsilk

cornsilk :: Color

#cornflowerblue

cornflowerblue :: Color

#coral

coral :: Color

#chocolate

chocolate :: Color

#chartreuse

chartreuse :: Color

#cadetblue

cadetblue :: Color

#burlywood

burlywood :: Color

#brown

brown :: Color

#blueviolet

blueviolet :: Color

#blue

blue :: Color

#blanchedalmond

blanchedalmond :: Color

#bisque

bisque :: Color

#beige

beige :: Color

#azure

azure :: Color

#aquamarine

aquamarine :: Color

#aqua

aqua :: Color

#antiquewhite

antiquewhite :: Color

#aliceblue

aliceblue :: Color