Finds the color in between two colors.

colorInBetween.js

function colorInBetween(color1, color2){
    function toNumber(hexStr){ return parseInt('0x'+hexStr); }
	function toColorObject(color){
		var obj = {};
		obj.red   = toNumber(color.slice(1,3));
		obj.green = toNumber(color.slice(3,5));
		obj.blue  = toNumber(color.slice(5,7));
		return obj;
	}
	function getAverage(val1, val2){ 
		return (val1 < val2) 
			? Math.floor(((val2 - val1)/2)+val1) 
			: Math.floor(((val1 - val2)/2)+val2);
	}
	
	c1 = toColorObject(color1);
	c2 = toColorObject(color2);
	c3 = {};
	
	c3.red 	= getAverage(c1.red, c2.red);
	c3.green	= getAverage(c1.green, c2.green);
	c3.blue 	= getAverage(c1.blue, c2.blue);
	
	return ('#' 	+ Number(c3.red).toString(16) 
				+ Number(c3.green).toString(16) 
				+ Number(c3.blue).toString(16));
}

console.log(colorInBetween('#e74c3c', '#f1c40f'));