onecolor


JavaScript color calculation toolkit for node.js and the browser.

Features:

- RGB, HSV, HSL, and CMYK colorspace support (experimental implementations of LAB and XYZ)
- Legal values for all channels are 0..1
- Instances are immutable -- a new object is created for each manipulation
- All internal calculations are done using floating point, so very little precision is lost due to rounding errors when converting between colorspaces
- Alpha channel support
- Extensible architecture -- implement your own colorspaces easily
- Chainable color manipulation
- Seamless conversion between colorspaces
- Outputs as hex, rgb(...), or rgba(...).

Module support:

- CommonJS / Node
- AMD / RequireJS
- Vanilla JS (installs itself on one.color)

Package managers:

- npm: npm install onecolor
- bower: bower install color

Small sizes:

- one-color.js   (Basic RGB, HSV, HSL)
- one-color-all.js   (Full RGB, HSV, HSL, CMYK, XYZ, LAB, named colors, helper functions)

Usage

In the browser (change one-color.js to one-color-all.js to gain
named color support):

``html


`

In the browser, the parser is exposed as a global named onecolor.
In node.js, it is returned directly with a require of the module
(after npm install onecolor):

`javascript
var color = require('onecolor');
console.warn(color('rgba(100%, 0%, 0%, .5)').alpha(0.4).cssa());
`

`output
rgba(255,0,0,0.4)
`

All of the above return color instances in the relevant color space
with the channel values (0..1) as instance variables:

`javascript
var myColor = color('#a9d91d');
myColor instanceof color.RGB; // true
myColor.red(); // 0.6627450980392157
`

You can also parse named CSS colors (works out of the box in node.js,
but the requires the slightly bigger one-color-all.js build in the
browser):

`javascript
color('maroon').lightness(0.3).hex(); // '#990000'
`

To turn a color instance back into a string, use the hex(), css(),
and cssa() methods:

`javascript
color('rgb(124, 96, 200)').hex(); // '#7c60c8'
color('#bb7b81').cssa(); // 'rgba(187,123,129,1)'
`

Color instances have getters/setters for all channels in all supported
colorspaces (red(), green(), blue(), hue(), saturation(), lightness(),
value(), alpha(), etc.). Thus you don't need to think about which colorspace
you're in. All the necessary conversions happen automatically:

`javascript
color('#ff0000') // Red in RGB
.green(1) // Set green to the max value, producing yellow (still RGB)
.hue(0.5, true) // Add 180 degrees to the hue, implicitly converting to HSV
.hex(); // Dump as RGB hex syntax: '#2222ff'
`

When called without any arguments, they return the current value of
the channel (0..1):

`javascript
color('#09ffdd').green(); // 1
color('#09ffdd').saturation(); // 0.9647058823529412
`

When called with a single numerical argument (0..1), a new color
object is returned with that channel replaced:

`javascript
var myColor = color('#00ddff');
myColor.red(0.5).red(); // .5

// ... but as the objects are immutable, the original object retains its value:
myColor.red(); // 0
`

When called with a single numerical argument (0..1) and true as
the second argument, a new value is returned with that channel
adjusted:

`javascript
color('#ff0000') // Red
.red(-0.1, true) // Adjust red channel by -0.1
.hex(); // '#e60000'
`

Alpha channel

All color instances have an alpha channel (0..1), defaulting to 1
(opaque). You can simply ignore it if you don't need it.

It's preserved when converting between colorspaces:

`javascript
color('rgba(10, 20, 30, .8)').green(0.4).saturation(0.2).alpha(); // 0.8
`

Comparing color objects

If you need to know whether two colors represent the same 8 bit color, regardless
of colorspace, compare their hex() values:

`javascript
color('#f00').hex() === color('#e00').red(1).hex(); // true
`

Use the equals method to compare two color instances within a certain
epsilon (defaults to 1e-9).

`javascript
color('#e00').lightness(0.00001, true).equals(color('#e00'), 1e-5); // false
color('#e00').lightness(0.000001, true).equals(color('#e00'), 1e-5); // true
`

Before comparing the equals method converts the other color to the right colorspace,
so you don't need to convert explicitly in this case either:

`javascript
color('#e00').hsv().equals(color('#e00')); // true
`

API overview

Color parser function, the recommended way to create a color instance:

`javascript
color('#a9d91d'); // Regular hex syntax
color('a9d91d'); // hex syntax, # is optional
color('#eee'); // Short hex syntax
color('rgb(124, 96, 200)'); // CSS rgb syntax
color('rgb(99%, 40%, 0%)'); // CSS rgb syntax with percentages
color('rgba(124, 96, 200, .4)'); // CSS rgba syntax
color('hsl(120, 75%, 75%)'); // CSS hsl syntax
color('hsla(120, 75%, 75%, .1)'); // CSS hsla syntax
color('hsv(220, 47%, 12%)'); // CSS hsv syntax (non-standard)
color('hsva(120, 75%, 75%, 0)'); // CSS hsva syntax (non-standard)
color([0, 4, 255, 120]); // CanvasPixelArray entry, RGBA
color(['RGB', 0.5, 0.1, 0.6, 0.9]); // The output format of color.toJSON()
`

The slightly bigger one-color-all.js build adds support for
the standard suite of named CSS colors:

`javascript
color('maroon');
color('darkolivegreen');
`

Existing onecolor instances pass through unchanged, which is useful
in APIs where you want to accept either a string or a color instance:

`javascript
color(color('#fff')); // Same as color('#fff')
`

Serialization methods:

`javascript
var myColor = color('#bda65b');

myColor.hex(); // 6-digit hex string: '#bda65b'
myColor.css(); // CSS rgb syntax: 'rgb(10,128,220)'
myColor.cssa(); // CSS rgba syntax: 'rgba(10,128,220,0.8)'
myColor.toString(); // For debugging: '[onecolor.RGB: Red=0.3 Green=0.8 Blue=0 Alpha=1]'
myColor.toJSON(); // ["RGB"|"HSV"|"HSL", , , , ]
`

Getters -- return the value of the channel (converts to other colorspaces as needed):

`javascript
var myColor = color('#bda65b');

myColor.red();
myColor.green();
myColor.blue();
myColor.hue();
myColor.saturation();
myColor.value();
myColor.lightness();
myColor.alpha();
myColor.cyan(); // one-color-all.js and node.js only
myColor.magenta(); // one-color-all.js and node.js only
myColor.yellow(); // one-color-all.js and node.js only
myColor.black(); // one-color-all.js and node.js only
`

Setters -- return new color instances with one channel changed:

`javascript
color.red()
color.green()
color.blue()
color.hue()
color.saturation()
color.value()
color.lightness()
color.alpha()
color.cyan() // one-color-all.js and node.js only
color.magenta() // one-color-all.js and node.js only
color.yellow() // one-color-all.js and node.js only
color.black() // one-color-all.js and node.js only
`

Adjusters -- return new color instances with the channel adjusted by
the specified delta (0..1):

`javascript
color.red(, true)
color.green(, true)
color.blue(, true)
color.hue(, true)
color.saturation(, true)
color.value(, true)
color.lightness(, true)
color.alpha(, true)
color.cyan(, true) // one-color-all.js and node.js only
color.magenta(, true) // one-color-all.js and node.js only
color.yellow(, true) // one-color-all.js and node.js only
color.black(, true) // one-color-all.js and node.js only
`

Comparison with other color objects, returns true or false (epsilon defaults to 1e-9):

`javascript
color.equals(otherColor[, ])
`

Mostly for internal (and plugin) use:

"Low level" constructors, accept 3 or 4 numerical arguments (0..1):

`javascript
new onecolor.RGB(, , [, ])
new onecolor.HSL(, , [, ])
new onecolor.HSV(, , [, ])
`

The one-color-all.js build includes CMYK support:

`javascript
new onecolor.CMYK(, , , [, ])
`

All color instances have rgb(), hsv(), and hsl() methods for
explicitly converting to another color space. Like the setter and
adjuster methods they return a new color object representing the same
color in another color space.

If for some reason you need to get all the channel values in a
specific colorspace, do an explicit conversion first to cut down on
the number of implicit conversions:

`javascript
var myColor = color('#0620ff').lightness(+0.3).rgb();

console.log(myColor.red() + ' ' + myColor.green() + ' ' + myColor.blue());
`

`output
0 0.06265060240963878 0.5999999999999999
`

Building

`
git clone https://github.com/One-com/one-color.git
cd one-color
npm install
npm run build
`

If you aren't up for a complete installation, there are pre-built
packages in the repository as well as the npm package:

- Basic library: one-color.js
- Full library including named color support: one-color-all.js

License

onecolor is licensed under a standard 2-clause BSD license -- see the LICENSE` file for details.