sweep.js

About

sweep.js is a small JavaScript library (5kb zipped) that enables proper color transitions through the HSL and HUSL spaces. Ordinary CSS transitions or existing frameworks convert HSL colors to RGB before transitioning. sweep.js addresses this by letting you transition through the color spectrum.

I've written an in-depth post about the need for HSL transitions here.

Install

bower install -S sweep

...or just visit the repo.

Sweep's dependencies are bundled; all you have to do is include the script.

<script src="path/to/sweep.js"></script>

Sweep is wrapped with UMD, so it'll also work as a module in your system of choice.

Usage

Using sweep.js to transition an element's color is easy. Whenever you want to trigger an HSL sweep, call:

sweep(target, properties, fromColor, toColor[, options])

• target : element that you wish to animate
• properties : CSS properties that you wish to animate (string or array of strings)
• fromColor : initial color before the transition
• toColor : final color after the transition
• options (optional) : an object that can set the following:
  • callback : function to be called once the animation finishes
  • direction : clockwise (1) or counterclockwise (-1)
  • duration : time (in ms) to complete the animation
  • space : 'HSL', 'HUSL', or 'RGB'

Examples

//click

var ex1 = document.querySelector('#ex1');
ex1.addEventListener('click', function() {
  sweep(ex1, 'backgroundColor', '#a8f', '#a8f', {direction: -1, duration: 2000});
}, false);

//hover

var ex2 = document.querySelector('#ex2');

ex2.addEventListener('mouseenter', function() {
  sweep(ex2, 'backgroundColor', getStyle(ex2, 'background-color'), '#0fa');
}, false);

ex2.addEventListener('mouseleave', function() {
  sweep(ex2, 'backgroundColor', getStyle(ex2, 'background-color'), '#a8f');
}, false);

Check it out on GitHub