$('#cssmenu li.active').addClass('open').children('ul').show(); 
$('#cssmenu li.has-sub>a').on('click', function(){
	$(this).removeAttr('href');
	var element = $(this).parent('li');
	if (element.hasClass('open')) {
	element.removeClass('open');
	element.find('li').removeClass('open');
	element.find('ul').slideUp();
	}
	else {
	element.addClass('open');
	element.children('ul').slideDown();
	element.siblings('li').children('ul').slideUp();
	element.siblings('li').removeClass('open');
	element.siblings('li').find('li').removeClass('open');
	element.siblings('li').find('ul').slideUp();
	}
});

$('#cssmenu>ul>li.has-sub>a').append('<span class="holder"></span>');

(function getColor() {
	var r, g, b;
	var textColor = $('#cssmenu').css('color');
	textColor = textColor.slice(4);
	r = textColor.slice(0, textColor.indexOf(','));
	textColor = textColor.slice(textColor.indexOf(' ') + 1);
	g = textColor.slice(0, textColor.indexOf(','));
	textColor = textColor.slice(textColor.indexOf(' ') + 1);
	b = textColor.slice(0, textColor.indexOf(')'));
	var l = rgbToHsl(r, g, b);
	if (l > 0.7) {
	$('#cssmenu>ul>li>a').css('text-shadow', '0 1px 1px rgba(0, 0, 0, .35)');
	$('#cssmenu>ul>li>a>span').css('border-color', 'rgba(0, 0, 0, .35)');
	}
	else
	{
	$('#cssmenu>ul>li>a').css('text-shadow', '0 1px 0 rgba(255, 255, 255, .35)');
	$('#cssmenu>ul>li>a>span').css('border-color', 'rgba(255, 255, 255, .35)');
	}
})();

function rgbToHsl(r, g, b) {
	r /= 255, g /= 255, b /= 255;
	var max = Math.max(r, g, b), min = Math.min(r, g, b);
	var h, s, l = (max + min) / 2;

	if(max == min){
		h = s = 0;
	}
	else {
		var d = max - min;
		s = l > 0.5 ? d / (2 - max - min) : d / (max + min);
		switch(max){
			case r: h = (g - b) / d + (g < b ? 6 : 0); break;
			case g: h = (b - r) / d + 2; break;
			case b: h = (r - g) / d + 4; break;
		}
		h /= 6;
	}
	return l;
}

<!-- jQuery -->
<script src="http://code.jquery.com/jquery-latest.min.js"></script>

<!-- Icon Library -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.5.0/css/font-awesome.min.css">