color

is

Signature

color.is (value)

Description

Returns true if value is a valid color recognized by chroma.js. Accepts hex strings, CSS color names, RGB/HSL notation, and other formats supported by chroma.js.

Parameters

Name	Type	Required	Description
value	any	yes	The value to test

Returns

Type	Description
boolean	true if the value is a valid color, false otherwise

Examples

color.is('#ff0000')
// true

color.is('red')
// true

color.is('hsl(0, 100%, 50%)')
// true

color.is('not-a-color')
// false

color.is(42)
// false

contrast

Signature

color.contrast (value, light = 'white', dark = 'black')

Description

Returns either light or dark depending on which provides the better contrast ratio against value. Useful for picking a readable foreground color on a given background.

Parameters

Name	Type	Required	Description
value	string	yes	The background color to test against
light	string	no	The color to return when a light foreground is preferred. Defaults to 'white'
dark	string	no	The color to return when a dark foreground is preferred. Defaults to 'black'

Returns

Type	Description
string	Either light or dark, whichever contrasts best with value

Examples

color.contrast('#ffffff')
// 'black'

color.contrast('#000000')
// 'white'

color.contrast('#1976d2', '#e3f2fd', '#0d47a1')
// '#e3f2fd'

scale

Signature

color.scale (options)

Description

Creates a chroma.js color scale from a set of colors, optionally constrained by a domain and/or class boundaries. Returns a chroma scale function that maps numeric values to colors.

Parameters

Name	Type	Required	Description
options	object	yes	Scale configuration
options.colors	string[]	yes	Array of colors defining the scale
options.domain	number[]	no	The [min, max] range of input values
options.classes	number | number[]	no	Number of discrete classes, or an array of class breakpoints

Returns

Type	Description
ChromaScale	A chroma.js scale function callable with a value in the domain

Examples

// Continuous scale between two colors
const scale = color.scale({ colors: ['white', 'red'] })
scale(0.5).hex()
// '#ff8080'

// Scale with a numeric domain
const scale = color.scale({ colors: ['blue', 'red'], domain: [0, 100] })
scale(75).hex()
// '#bf0040'

// Scale with a fixed number of discrete classes
const scale = color.scale({ colors: ['yellow', 'red'], domain: [0, 100], classes: 5 })

// Scale with explicit class breakpoints
const scale = color.scale({ colors: ['green', 'yellow', 'red'], classes: [0, 30, 70, 100] })