Convert CSS hex color to rgba() with opacity

css-hex-to-rgba

// adapted from awesomest http://gist.github.com/lrvick/2080648
var hexToRGB = function ( hex ) {
    var r,g,b;
  	hex = parseInt( hex.replace('#',''), 16 );
    r = hex >> 16;
    g = hex >> 8 & 0xFF;
    b = hex & 0xFF;
    return [r,g,b];
};

// add opacity
var colorOpacity = function ( hex, opacity ) {
    return 'rgba('+ hexToRGB( hex ).join(',') + ',' + opacity +')';
};

// test
var newColor = colorOpacity( '#663399', 0.4 );