Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/brehaut/color-js

A color management API for javascript
https://github.com/brehaut/color-js

color javascript

Last synced: 16 days ago
JSON representation

A color management API for javascript

Awesome Lists containing this project

README 

        
# *Notice:* No longer maintained



This library was created during a time where color support in CSS was minimal, and has since been superceded by both newer libraries and CSS itself. As of 2021 [colorjs.io](https://colorjs.io) is a project aiming to produce an correct and comprehensive color library for javascript that is colorspace aware and built on color science. 



*****



# Readme



Color.js provides an API to do simple color management in javascript. Color objects provide methods to do a number of common, useful operations independent of the underlying color model they need. 



The library supports RGB, HSV and HSL color models, along with alpha channel on all of them. CSS string representations of colors are supported for convenience. If you need colorspace management that correlates to human perception rather than display technology, [colorspace.js](http://boronine.com/colorspaces.js/) looks like an excellent library.



Color objects are always immutable; all operations on them return new objects.



This API is designed for correctness and clarity first, but operates at the expense of some performance. If you need raw performance look for a library that forces you to do the cloning and conversion yourself, rather than implicitly as this one does.



> **Note:** In 2017 it's quite possible that you don't need this library, particularly for client side tasks; many use-cases can simply be achieved using CSS RGB, HSV, and HSL color syntaxes.



# Using the library 



Once you have included the library in your page, you can access the public namespace `net.brehaut` (reverse DNS scheme). The only export from `color.js` is the `Color` factory function. You may wish 

to import this into your local scope, eg:

  

    var Color = net.brehaut.Color;



You can use the library in a CommonJS environment, too:



    var Color = require('./color').Color;



`Color` will create a new object for you from an object, string, or array. Note that this is a factory function, _not_ a constructor. eg:



    var Green = Color("#00FF00");

    var Red = Color({hue: 0, saturation: 1, value: 1});

    var Blue = Color("rgb(0,0,255)");

    var Cyan = Color({hue: 180, saturation: 1, lightness: 0.5});

    var Magenta = Color("hsl(300, 100%, 50%)");

    var Yellow = Color([255,255,0]);



Each method on a color either returns a new color (or set of colors) or returns a value. You can chain manipulation methods together as much as you need. Eg



    var C1 = Red.shiftHue(45).darkenByRatio(0.5).desaturateByAmount(0.1);



A common use case for this code is to set page elements colors to calculated values, the method `toCSS` provides a string for you to use. eg:



    document.getElementById('myElement').style.backgroundColor = C1.toCSS();



# Methods



There are three sorts of operations available on color objects; accessor methods (eg `getHue`/`setHue`), methods that manipulate the color and return a new object (eh `shiftHue`)  or methods that return arrays of colors (eg, `splitComplementaryScheme`), and methods that do conversion and construction (eg `toCSS`).



All values are a float from 0 to 1, with the exception of _hue_ which is a degree (from 0 to 360). 



## Notes on terminology



- A ratio multiplies the existing property by the ratio.

- An amount is just added directly to the existing value.



If you have a saturation of 0.7 and you apply a *ratio* of 0.5 the new color has a saturation of 0.35. If you then add an *amount* of 0.15 to that color’s saturation the final color will have a saturation of 0.5.



### Accessor Methods

These methods are automatically generated by the API and are used to access the properties of the object. It is advisable to use these methods than try to access the property directly as the API makes no guarantees about the specific model members available. 



 * `getRed()` : Number

 * `setRed( newRed )` : Color

 * `getGreen()`: Number 

 * `setGreen( newGreen )` : Color

 * `getBlue()` : Number

 * `setBlue( newBlue )`: Color

 * `getHue()` : Number (degrees)

 * `setHue( newHue )` : color

 * `getSaturation()` : Number

 * `setSaturation( newSaturation )` : Color

 * `getValue()` : Number

 * `setValue( newValue )` : Color

 * `getLightness()` : Number

 * `setLightness( newValue )` : Color

 * `getLuminance()` : Number --- returns a number between 0 and 1 that represents how bright this color appears on a conventional monitor.

 * `getAlpha()` : Number

 * `setAlpha( newAlpha )` : Number 



### Color Methods



The following methods all return a new color.



 * `shiftHue( degrees )` : Color

 * `darkenByAmount( amount )` : Color

 * `darkenByRatio( ratio )` : Color

 * `lightenByAmount( amount )` : Color

 * `lightenByRatio( amount )` : Color

 * `devalueByAmount( amount )` : Color

 * `devalueByRatio( ratio )` : Color

 * `valueByAmount( amount )` : Color

 * `valueByRatio( amount )` : Color

 * `desaturateByAmount( amount )` : Color

 * `desaturateByRatio( ratio )` : Color

 * `saturateByAmount( amount )` : Color

 * `saturateByRatio( ratio )` : Color

 * `blend( color , alpha )` : Color --- returns a new color that is self blended with alpha of `color`. eg `black.blend ( white , 0 )` is black, `black.blend ( white , 0.5 )` is grey and `black.blend ( white , 1 )` is white.



The following methods return a list of colors



 * `schemeFromDegrees( listOfdegrees )` : List of Colors 

 * `complementaryScheme( )` : List of Colors 

 * `splitComplementaryScheme( )` : List of Colors 

 * `splitComplementaryCWScheme( )` : List of Colors 

 * `splitComplementaryCCWScheme( )` : List of Colors 

 * `triadicScheme( )` : List of Colors 

 * `clashScheme( )` : List of Colors 

 * `tetradicScheme( )` : List of Colors 

 * `fourToneCWScheme( )` : List of Colors 

 * `fourToneCCWScheme( )` : List of Colors 

 * `fiveToneAScheme( )` : List of Colors

 * `fiveToneBScheme( )` : List of Colors

 * `fiveToneCScheme( )` : List of Colors

 * `fiveToneDScheme( )` : List of Colors

 * `fiveToneEScheme( )` : List of Colors   

 * `sixToneCWScheme( )` : List of Colors 

 * `sixToneCCWScheme( )` : List of Colors 

 * `neutralScheme( )` : List of Colors 

 * `analogousScheme( )` : List of Colors 



### Conversion and Construction



 * `fromObject( o )` : Color --- `o` is an object with values from a color model, a css string, or an RGB array.

 * `toCSS([bytesPerChannel])` : String --- css hexdecimal representation. `bytesPerChannel` defaults to 2

 * `toString()` : String --- returns CSS representation

 * `toHSV()` : Color

 * `toRGB()` : Color

 * `toHSL()` : Color



## Type definitions



Users of [TypeScript](http://typescriptlang.org/) can find type definitions in `color.d.ts`.



# Demo

* [Using color-js with Angular 2](https://plnkr.co:443/Y7scVM)



# Changes





  
Jan 24, 2017


  
Version 1.0.4: Changed type declaration for using with Angular 2



  
May 12, 2015


  
Version 1.0.2: Add package.json for NPM publishing.



  
May 3, 2013


  
Version 1.0.1: Bug fix for alpha support in achromatic HSV to RGB.


  

  
May 1, 2013


  
Version 1.0

    
    

          
  • Alpha channels are supported on all color models.
    • 

        


  


    

  
April 16, 2013


  
Version 0.6

    
    

          
  • fromArray RGB factory added. This factory takes an array of three RGB values as ints from 0-255.
    • 

       


    

    

  
March 4, 2013


  
Version 0.5

    
    

          
  • Fixes bug where lightenBy…/darkenBy… used value property from HSV model, despite HSL now being supported.
    • 

          
  • 

    valueBy…/devalueBy… methods added. These behave like the old lightenBy…/darkenBy… methods.
    • 

          
  • Module function now uses strict mode.
    •  

        


  


    

  
July 24, 2010


  
Version 0.4

    
    

          
  • Support for HSL color model
    • 

          
  • Common.JS module support
    • 

          
  • Minor bug fixes
    • 

        


  



    

 
January 14, 2008


 
Version 0.3 released

   
    

         
  • 

    JSLint is now happy with it.
    • 

         
  • Approx 25% faster by caching factory constructor functions — effectively unrolls object

    • 

       


 



 
January 13, 2008


 
Version 0.2 released 

   
    

         
  • Code tided up, now with comments
    • 

         
  • Docs written
    • 

         
  • 

               Small edges cases implemented, eg, a black Color is returned if invalid arguments are 

               passed

         
    • 

         
  • CSS named colors are supported
    •