<script type="text/javascript">
 /*
 // 作者 yanue
 // 参数：
 // startColor：开始颜色hex
 // endColor：结束颜色hex
 // step:几个阶级（几步）
 */
 function gradientColor(startColor,endColor,step){
  startRGB = this.colorRgb(startColor);//转换为rgb数组模式
  startR = startRGB[0];
  startG = startRGB[1];
  startB = startRGB[2];
  endRGB = this.colorRgb(endColor);
  endR = endRGB[0];
  endG = endRGB[1];
  endB = endRGB[2];
  sR = (endR-startR)/step;//总差值
  sG = (endG-startG)/step;
  sB = (endB-startB)/step;
  var colorArr = [];
  for(var i=0;i<step;i++){
  //计算每一步的hex值 
   var hex = this.colorHex('rgb('+parseInt((sR*i+startR))+','+parseInt((sG*i+startG))+','+parseInt((sB*i+startB))+')');
   colorArr.push(hex);
  }
  return colorArr;
 }
 // 将hex表示方式转换为rgb表示方式(这里返回rgb数组模式)
 gradientColor.prototype.colorRgb = function(sColor){
  var reg = /^#([0-9a-fA-f]{3}|[0-9a-fA-f]{6})$/;
  var sColor = sColor.toLowerCase();
  if(sColor && reg.test(sColor)){
   if(sColor.length === 4){
    var sColorNew = "#";
    for(var i=1; i<4; i+=1){
     sColorNew += sColor.slice(i,i+1).concat(sColor.slice(i,i+1));
    }
    sColor = sColorNew;
   }
   //处理六位的颜色值
   var sColorChange = [];
   for(var i=1; i<7; i+=2){
    sColorChange.push(parseInt("0x"+sColor.slice(i,i+2)));
   }
   return sColorChange;
  }else{
   return sColor;
  }
 };
 // 将rgb表示方式转换为hex表示方式
 gradientColor.prototype.colorHex = function(rgb){
  var _this = rgb;
  var reg = /^#([0-9a-fA-f]{3}|[0-9a-fA-f]{6})$/;
  if(/^(rgb|RGB)/.test(_this)){
   var aColor = _this.replace(/("").split(",");
   var strHex = "#";
   for(var i=0; i<aColor.length; i++){
    var hex = Number(aColor[i]).toString(16);
    hex = hex<10 "0"){
     hex += hex;
    }
    strHex += hex;
   }
   if(strHex.length !== 7){
    strHex = _this;
   }
   return strHex;
  }else if(reg.test(_this)){
   var aNum = _this.replace(/#/,"").split("");
   if(aNum.length === 6){
    return _this;
   }else if(aNum.length === 3){
    var numHex = "#";
    for(var i=0; i<aNum.length; i+=1){
     numHex += (aNum[i]+aNum[i]);
    }
    return numHex;
   }
  }else{
   return _this;
  }
 }
 var gradient = new gradientColor('#013548','#554851',10);
 console.log(gradient);//控制台输出
 alert(gradient);
</script>