当你在3D环境中工作时(webGL, ThreeJS)，你有时需要为网格的不同面创建3个值，基本的一个(主色)，一个浅一点的和一个深一点的:

material.color.set( 0x660000, 0xff0000, 0xff6666 ); // red cube

我们可以从主RBG颜色创建这3个值:255,0,0

function rgbToHex(rgb) { 
  var hex = Number(rgb).toString(16);
  if (hex.length < 2) {
       hex = "0" + hex;
  }
  return hex;
};

function convertToHex(r,g,b) { 

    var fact = 100;  // contrast 
    var code = '0x';

    // main color
    var r_hexa = rgbToHex(r);
    var g_hexa = rgbToHex(g);
    var b_hexa = rgbToHex(b);

    // lighter
    var r_light = rgbToHex(Math.floor(r+((1-(r/255))*fact)));
    var g_light = rgbToHex(Math.floor(g+((1-(g/255))*fact)));
    var b_light = rgbToHex(Math.floor(b+((1-(b/255))*fact)));

    // darker
    var r_dark = rgbToHex(Math.floor(r-((r/255)*(fact*1.5)))); // increase contrast
    var g_dark = rgbToHex(Math.floor(g-((g/255)*(fact*1.5))));
    var b_dark = rgbToHex(Math.floor(b-((b/255)*(fact*1.5))));

    var hexa = code+r_hexa+g_hexa+b_hexa;
    var light = code+r_light+g_light+b_light;
    var dark = code+r_dark+g_dark+b_dark;

    console.log('HEXs -> '+dark+" + "+hexa+" + "+light)

    var colors = [dark, hexa, light]; 
    return colors;

}

在你的ThreeJS代码中简单地写:

var material = new THREE.MeshLambertMaterial();
var c = convertToHex(255,0,0); // red cube needed
material.color.set( Number(c[0]), Number(c[1]), Number(c[2]) );

结果:

//                                 dark      normal     light
convertToHex(255,255,255) HEXs -> 0x696969 + 0xffffff + 0xffffff
convertToHex(255,0,0) HEXs -> 0x690000 + 0xff0000 + 0xff6464
convertToHex(255,127,0) HEXs -> 0x690000 + 0xff0000 + 0xff6464
convertToHex(100,100,100) HEXs -> 0x292929 + 0x646464 + 0xa0a0a0
convertToHex(10,10,10) HEXs -> 0x040404 + 0x0a0a0a + 0x6a6a6a

我需要一个函数，接受无效值太像

Rgb (- 255,255,255) Rgb (510, 255, 255)

这是@cwolves answer的衍生

function rgb(r, g, b) {
  this.c = this.c || function (n) {
    return Math.max(Math.min(n, 255), 0)
  };

  return ((1 << 24) + (this.c(r) << 16) + (this.c(g) << 8) + this.c(b)).toString(16).slice(1).toUpperCase();
}

如果你需要比较两个颜色值(给定为RGB，名称颜色或十六进制值)或转换为hex使用HTML5 canvas对象。

var canvas = document.createElement("canvas");
var ctx = this.canvas.getContext('2d');

ctx.fillStyle = "rgb(pass,some,value)";
var temp =  ctx.fillStyle;
ctx.fillStyle = "someColor";

alert(ctx.fillStyle == temp);

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(',')+')';
}

这个代码片段将十六进制转换为rgb, rgb转换为十六进制。

视图演示

function hexToRgb(str) { 
    if ( /^#([0-9a-f]{3}|[0-9a-f]{6})$/ig.test(str) ) { 
        var hex = str.substr(1);
        hex = hex.length == 3 ? hex.replace(/(.)/g, '$1$1') : hex;
        var rgb = parseInt(hex, 16);               
        return 'rgb(' + [(rgb >> 16) & 255, (rgb >> 8) & 255, rgb & 255].join(',') + ')';
    } 

    return false; 
}

function rgbToHex(red, green, blue) {
    var out = '#';

    for (var i = 0; i < 3; ++i) {
        var n = typeof arguments[i] == 'number' ? arguments[i] : parseInt(arguments[i]);

        if (isNaN(n) || n < 0 || n > 255) {
            return false;
        }

        out += (n < 16 ? '0' : '') + n.toString(16);
    }
    return out
}

这可以用于从计算样式属性中获取颜色:

function rgbToHex(color) {
    color = ""+ color;
    if (!color || color.indexOf("rgb") < 0) {
        return;
    }

    if (color.charAt(0) == "#") {
        return color;
    }

    var nums = /(.*?)rgb\((\d+),\s*(\d+),\s*(\d+)\)/i.exec(color),
        r = parseInt(nums[2], 10).toString(16),
        g = parseInt(nums[3], 10).toString(16),
        b = parseInt(nums[4], 10).toString(16);

    return "#"+ (
        (r.length == 1 ? "0"+ r : r) +
        (g.length == 1 ? "0"+ g : g) +
        (b.length == 1 ? "0"+ b : b)
    );
}

// not computed 
<div style="color: #4d93bc; border: 1px solid red;">...</div> 
// computed 
<div style="color: rgb(77, 147, 188); border: 1px solid rgb(255, 0, 0);">...</div>

console.log( rgbToHex(color) ) // #4d93bc
console.log( rgbToHex(borderTopColor) ) // #ff0000

裁判:https://github.com/k-gun/so/blob/master/so_util.js