ariColor is a PHP library that will hopefully help WordPress theme developers do their job easier and more effectively.
It does not provide you with methods like lighten(), darken() etc. Instead, what it does is give you the ability to create these yourself with extreme ease by giving you all the properties of a color at hand, and allowing you to manipulate them however you see fit.
Example:
First, let's create our color object:
$color = ariColor::newColor( '#049CBE', 'hex' );