Generate evenly distributed spectrum in JavaScript

jsspectrum.js

hslToRgb = function(_h, s, l) {	
	var h = Math.min(_h, 359)/60;
	
	var c = (1-Math.abs((2*l)-1))*s;
	var x = c*(1-Math.abs((h % 2)-1));
	var m = l - (0.5*c);
	
	var r = m, g = m, b = m;
	
	if (h < 1) {
		r += c, g = +x, b += 0;
	} else if (h < 2) {
		r += x, g += c, b += 0;
	} else if (h < 3) {
		r += 0, g += c, b += x;
	} else if (h < 4) {
		r += 0, g += x, b += c;
	} else if (h < 5) {
		r += x, g += 0, b += c;
	} else if (h < 6) {
		r += c, g += 0, b += x;
	} else {
		r = 0, g = 0, b = 0;
	}
	
	return 'rgb(' + Math.floor(r*255) + ', ' + Math.floor(g*255) + ', ' + Math.floor(b*255) + ')';
}

createSpectrum = function(length) {
	var colors = [];
	// 270 because we don't want the spectrum to circle back
	var step = 270/length;
	for (var i = 1; i <= length; i++) {
		var color = hslToRgb((i)*step, 0.5, 0.5);
		colors.push(color);
	}
	
	return colors;
}