hexToRgb的另一个版本:

function hexToRgb(hex) {
    var bigint = parseInt(hex, 16);
    var r = (bigint >> 16) & 255;
    var g = (bigint >> 8) & 255;
    var b = bigint & 255;

    return r + "," + g + "," + b;
}

编辑:3/28/2017 这是另一种似乎更快的方法

function hexToRgbNew(hex) {
  var arrBuff = new ArrayBuffer(4);
  var vw = new DataView(arrBuff);
  vw.setUint32(0,parseInt(hex, 16),false);
  var arrByte = new Uint8Array(arrBuff);

  return arrByte[1] + "," + arrByte[2] + "," + arrByte[3];
}

编辑:8/11/2017 经过更多测试后，上面的新方法并没有更快:(。虽然这是一种有趣的替代方式。

我意识到这个问题有很多答案，但如果你像我一样，你知道你的HEX总是6个字符，带或不带#前缀，那么如果你想做一些快速内联的东西，这可能是最简单的方法。它不关心是否以散列开始。

var hex = "#ffffff";
var rgb = [
    parseInt(hex.substr(-6,2),16),
    parseInt(hex.substr(-4,2),16),
    parseInt(hex.substr(-2),16)
];

我给洛达什做了这个。它将一个RGB字符串，如“30,209,19”转换为其对应的十六进制字符串“#1ed113”:

var rgb = '30,209,19';

var hex = _.reduce(rgb.split(','), function(hexAccumulator, rgbValue) {
    var intColor = _.parseInt(rgbValue);

    if (_.isNaN(intColor)) {
        throw new Error('The value ' + rgbValue + ' was not able to be converted to int');
    }

    // Ensure a value such as 2 is converted to "02".
    var hexColor = _.padLeft(intColor.toString(16), 2, '0');

    return hexAccumulator + hexColor;
}, '#');

以下是我的看法:

function rgbToHex(red, green, blue) {
  const rgb = (red << 16) | (green << 8) | (blue << 0);
  return '#' + (0x1000000 + rgb).toString(16).slice(1);
}

function hexToRgb(hex) {
  const normal = hex.match(/^#([0-9a-f]{2})([0-9a-f]{2})([0-9a-f]{2})$/i);
  if (normal) return normal.slice(1).map(e => parseInt(e, 16));

  const shorthand = hex.match(/^#([0-9a-f])([0-9a-f])([0-9a-f])$/i);
  if (shorthand) return shorthand.slice(1).map(e => 0x11 * parseInt(e, 16));

  return null;
}

这段代码接受#fff和#ffffff变量和不透明度。

function hex2rgb(hex, opacity) {
        var h=hex.replace('#', '');
        h =  h.match(new RegExp('(.{'+h.length/3+'})', 'g'));

        for(var i=0; i<h.length; i++)
            h[i] = parseInt(h[i].length==1? h[i]+h[i]:h[i], 16);

        if (typeof opacity != 'undefined')  h.push(opacity);

        return 'rgba('+h.join(',')+')';
}

我假设您指的是html风格的十六进制符号，即#rrggbb。你的代码几乎是正确的，只是顺序颠倒了。它应该是:

var decColor = red * 65536 + green * 256 + blue;

此外，使用位移位可能会让它更容易阅读:

var decColor = (red << 16) + (green << 8) + blue;