<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>extend</title>
</head>
<body>
<input type="button" value="OK" style="color:red">
<script src="http://apps.bdimg.com/libs/jquery/2.1.4/jquery.min.js"></script>
<script>
;(function($) {
$.fn.extend({
"color":function(value){
if( value== undefined){
return this.css("color")
}else{
return this.css("color",value)
}
}
})
})(jQuery)
var x = $("input").color("pink");
</script>
</body>
</html>