rgb与十六进制互相转换

 //十六进制颜色值的正则表达式
  var reg = /^#([0-9a-fA-f]{3}|[0-9a-fA-f]{6})$/;
//转换为十六进制方法
             function colorHex(string){
                if(/^(rgb|RGB)/.test(string)){
                    var aColor = string.replace(/(?:(|)|rgb|RGB)*/g,"").split(",");
                    var strHex = "#";
                    for(var i=0; i<aColor.length; i++){
                        var hex = Number(aColor[i]).toString(16);
                        if(hex === "0"){
                            hex += hex; 
                        }
                        strHex += hex;
                    }
                        if(strHex.length !== 7){
                            strHex = string;  
                        }
                        return strHex;
                }else if(reg.test(string)){
                        var aNum = string.replace(/#/,"").split("");
                        if(aNum.length === 6){
                            return string;    
                        }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 string;    

                }
            }
            console.log(colorHex("RGB(255, 255, 0)"))

 //十六进制颜色值的正则表达式
            var reg = /^#([0-9a-fA-f]{3}|[0-9a-fA-f]{6})$/;
/*16进制颜色转为RGB格式*/
           function colorRgb(string){
                var sColor = string.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 "RGB(" + sColorChange.join(",") + ")";
                }else{
                    return sColor;  
                }
            }
            console.log(colorRgb("#00538b"))