URL-encode color SASS function / convert color to hex SASS function

library.scss

//does not work with colors containing alpha
@function encodecolor($string) {
	@if type-of($string) == 'color' {
		@if $string != transparent {
			$hex: str-slice(ie-hex-str($string), 4);
			$string:unquote("#{$hex}");
    			$string: '%23' + $string;
		}
	}
	@return $string;
}