getaveragecolour.js

function getAverageColour() {
    var colour;
    var r = 0;
    var g = 0;
    var b = 0;

    var lis = $('.pen li');

    for (var index = 0, len = lis.length; index < len; index++) {
        var li = $(lis[index]);

        r = r+ parseInt(li.attr('red'));
        g = g+ parseInt(li.attr('green'));
        b = g+ parseInt(li.attr('blue'));

        if (index+1 == $('.pen').children().length) {                    
            colour = {r:Math.round(r/(index+1)), g:Math.round(g/(index+1)), b:Math.round(b/(index+1))};
            return colour;
        }
    }
}