使用getRandomColor()代替“#0000FF”:

function getRandomColor() { var letters = '0123456789ABCDEF'; var color = '#'; for (var i = 0; i < 6; i++) { color += letters[Math.floor(Math.random() * 16)]; } return color; } function setRandomColor() { $("#colorpad").css("background-color", getRandomColor()); } <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <div id="colorpad" style="width:300px;height:300px;background-color:#000"> </div> <button onclick="setRandomColor()">Random Color</button>

您还可以使用在所有优秀浏览器(http://caniuse.com/#feat=css3-colors)上可用的HSL。

function randomHsl() {
    return 'hsla(' + (Math.random() * 360) + ', 100%, 50%, 1)';
}

这将给你只有明亮的颜色，你可以玩亮度，饱和度和阿尔法。

// es6
const randomHsl = () => `hsla(${Math.random() * 360}, 100%, 50%, 1)`

这是我的两个版本的随机十六进制代码生成器。

/* Slowest but shortest. */
"#000000".replace(/0/g,function(){return (~~(Math.random()*16)).toString(16);});    

/* Good performance with small size. */
"#"+(function(a,b){while(a--){b+=""+(~~(Math.random()*16)).toString(16);} return b;})(6,"");

/* Remy Sharp provided one that's the fastest but a little bit too long */
(function(h){return '#000000'.substr(0,7-h.length)+h})((~~(Math.random()*(1<<24))).toString(16))

有很多方法可以做到这一点。以下是我做的一些:

简短的一行代码，保证有效的颜色

'#'+(Math.random().toString(16)+'00000').slice(2,8)

生成6个随机十六进制数字(0-F)

function randColor() {
    for (var i=0, col=''; i<6; i++) {
        col += (Math.random()*16|0).toString(16);
    }
    return '#'+col;
}

// ES6 one-liner version
[..."000000"].map(()=>Math.random().toString(16)[2]).join("")

生成单独的HEX组件(00-FF)

function randColor2() {
    var r = ('0'+(Math.random()*256|0).toString(16)).slice(-2),
        g = ('0'+(Math.random()*256|0).toString(16)).slice(-2),
        b = ('0'+(Math.random()*256|0).toString(16)).slice(-2);
    return '#' +r+g+b;
}

过度设计的十六进制字符串(XORs 3输出一起形成颜色)

function randColor3() {
    var str = Math.random().toString(16) + Math.random().toString(16),
    sg = str.replace(/0./g,'').match(/.{1,6}/g),
    col = parseInt(sg[0], 16) ^ 
          parseInt(sg[1], 16) ^ 
          parseInt(sg[2], 16);
    return '#' + ("000000" + col.toString(16)).slice(-6);
}

我认为第一个回答是最简洁/有用的，但我只是写了一个初学者可能更容易理解的回答。

function randomHexColor(){
    var hexColor=[]; //new Array()
    hexColor[0] = "#"; //first value of array needs to be hash tag for hex color val, could also prepend this later

    for (i = 1; i < 7; i++)
    {
        var x = Math.floor((Math.random()*16)); //Tricky: Hex has 16 numbers, but 0 is one of them

        if (x >=10 && x <= 15) //hex:0123456789ABCDEF, this takes care of last 6 
        {
            switch(x)
            {
                case 10: x="a" 
                break;
                case 11: x="b" 
                break;
                case 12: x="c" 
                break;
                case 13: x="d" 
                break;
                case 14: x="e" 
                break;
                case 15: x="f" 
                break;  
            }
        }
        hexColor[i] = x;
    }
    var cString = hexColor.join(""); //this argument for join method ensures there will be no separation with a comma
    return cString;
}

var html = '';
var red;
var green;
var blue;
var rgbColor;

for ( var i = 1; i <= 100; i += 1) {
  red = Math.floor(Math.random() * 256 );
  green = Math.floor(Math.random() * 256 );
  blue = Math.floor(Math.random() * 256 );
  rgbColor = 'rgb(' + red + ',' + green + ',' + blue + ')';
  html += '<div style="background-color:' + rgbColor + '"></div>';  
}

document.write(html);