下面是源码 需要浏览器支持html5 
复制代码代码如下: 
html 
head 
/head 
body 
canvas id="colorPicker" onmousemove="showCurrentColor(event)" 
/canvas 
br/ 
div id="textResult" 
/div 
script type="text/javascript" 
if(document.createElement("canvas")){ 
if(document.getElementById("colorPicker").getContext){ 
var can = document.getElementById("colorPicker"); 
can.setAttribute("height",300); 
var cxt = can.getContext("2d"); 
var gradient = cxt.createLinearGradient(0.5,0.5,0,150);