FullCalendar alternate calendar colors.

alternate.js

//Globla variable outside of all functions
var altColor = 1;
//Global function
function isEven(n) {
   return n % 2 == 0;
}

//This goes inside the full calendar call
eventRender: function(event, element) {
					if(isEven(altColor)) {
						$(element).css("background-color", "red");
					}
					else {
						$(element).css("background-color", "blue");
					}
					altColor++;
				}