a light-weight color picker implemented with SVG
color picker
color picker是一个用原生js实现的轻量的拾色器，压缩后仅8KB，能实现选择颜色并返回颜色值（hsv值/rgb值）或者输入颜色值来预览颜色。
使用：
- 引入colorpicker.js和colorpicker.css
- 调用colorPicker()并传入一个dom节点，例如：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>color picker</title>
<link rel="stylesheet" href="colorpicker.css"></link>
<script type="text/javascript" src="colorpicker.js"></script>
</head>
<body>
<div id="someId">
<script type="text/javascript">
var someElement = document.getElementById('someId');
colorPicker(someElement);
</script>
</body>
</html>