$(document).ready(function() {
			// Colored panels parent
	var colorPanelParent = $('.js-color-panel-container'),
			// Colored panels
			colorPanels 		 = colorPanelParent.find('div'),
			// Number of colored panels
			numColorPanels	 = colorPanels.length,
			/** Max RGB val
			* 256 since the random() method returns a number
			* between 0 - 1 - including 0, but not 1.
			* This way the highest number will be 255 once
			* multiplied by the random number.
			*/ 
			rgbVal					 = 256;

	/**
	 * Color changer
	 */
	function colorChangeTimer() {
		setTimeout(function() {

			// Single panel on which to change color
			var _panelToChange = generateRandomNumber(numColorPanels - 1);

			// Change panel background color
			colorsToChange(_panelToChange);

			// Recursion
			colorChangeTimer();
		}, 150);
	}

	/**
	 * Generate random number between 0 - n.
	 * @param  {Number} ranNum: random index of panel to be changed
	 * @return {Number} (0 - n)
	 */
	function generateRandomNumber(ranNum) {
				// Highest possible number.
		var _upperLimit = ranNum,
				/**
				 * Randomized number
				 * Multiply result (greater than or equal to 0, but less than 1) by
				 * the upperLimit, then round to nearest whole number.
				 */
				result = Math.round(Math.random() * _upperLimit);

		// Return the random number for use in other functions.
		return result;
	}

	/**
	 * Change panel background color
	 * @param  {Number} index: index of color panel to be changed
	 */
	function colorsToChange(index) {
		var color1 = generateRandomNumber(rgbVal),
				color2 = generateRandomNumber(rgbVal),
				color3 = generateRandomNumber(rgbVal);
		$(colorPanels[index]).css('background-color', 'rgb(' + color1 + ', ' + color2 + ', ' + color3 + ')');
	}

	/**
	 * Loop through colorPanels and run colorsToChange()
	 * to change thier individual background colors.
	 * This occurs once on page load.
	 * @param  {Number} var i: iterator
	 */
	function changeColorsOnLoad() {
		for (var i = 0; i < numColorPanels; i++) {
			colorsToChange(i);
		};
	}

	changeColorsOnLoad();
	colorChangeTimer();
});