我为RGB和十六进制颜色做了一个小的Javascript颜色类，这个类还包括RGB和十六进制验证函数。我将代码作为一个片段添加到这个答案中。

var colorClass = function() { this.validateRgb = function(color) { return typeof color === 'object' && color.length === 3 && Math.min.apply(null, color) >= 0 && Math.max.apply(null, color) <= 255; }; this.validateHex = function(color) { return color.match(/^\#?(([0-9a-f]{3}){1,2})$/i); }; this.hexToRgb = function(color) { var hex = color.replace(/^\#/, ''); var length = hex.length; return [ parseInt(length === 6 ? hex['0'] + hex['1'] : hex['0'] + hex['0'], 16), parseInt(length === 6 ? hex['2'] + hex['3'] : hex['1'] + hex['1'], 16), parseInt(length === 6 ? hex['4'] + hex['5'] : hex['2'] + hex['2'], 16) ]; }; this.rgbToHex = function(color) { return '#' + ('0' + parseInt(color['0'], 10).toString(16)).slice(-2) + ('0' + parseInt(color['1'], 10).toString(16)).slice(-2) + ('0' + parseInt(color['2'], 10).toString(16)).slice(-2); }; }; var colors = new colorClass(); console.log(colors.hexToRgb('#FFFFFF'));// [255, 255, 255] console.log(colors.rgbToHex([255, 255, 255]));// #FFFFFF

从HEX转换为RGB，其中RGB是0到1范围内的浮点值:

#FFAA22→{r: 0.5, g: 0, b:1}

我改编了@Tim Down的回答:

function convertRange(value,oldMin,oldMax,newMin,newMax) {
  return (Math.round(((((value - oldMin) * (newMax - newMin)) / (oldMax - oldMin)) + newMin) * 10000)/10000)
}

function hexToRgbFloat(hex) {
  var result = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hex);
  return result ? {
    r: convertRange(parseInt(result[1],16), 0, 255, 0, 1),
    g: convertRange(parseInt(result[2],16), 0, 255, 0, 1),
    b: convertRange(parseInt(result[3],16), 0, 255, 0, 1)
  } : null;
}

console.log(hexToRgbFloat("#FFAA22")) // {r: 1, g: 0.6667, b: 0.1333}

一个简单的答案，将RGB转换为十六进制。这里颜色通道的值被限定在0到255之间。

function RGBToHex(r = 0, g = 0, b = 0) {
    // clamp and convert to hex
    let hr = Math.max(0, Math.min(255, Math.round(r))).toString(16);
    let hg = Math.max(0, Math.min(255, Math.round(g))).toString(16);
    let hb = Math.max(0, Math.min(255, Math.round(b))).toString(16);
    return "#" +
        (hr.length<2?"0":"") + hr +
        (hg.length<2?"0":"") + hg +
        (hb.length<2?"0":"") + hb;
}

HEX转RGB (ES6) +测试[2022]

convertHexToRgb.ts:

/**
 * RGB color regexp
 */
export const RGB_REG_EXP = /rgb\((\d{1,3}), (\d{1,3}), (\d{1,3})\)/;

/**
 * HEX color regexp
 */
export const HEX_REG_EXP = /^#?(([\da-f]){3}|([\da-f]){6})$/i;

/**
 * Converts HEX to RGB.
 *
 * Color must be only HEX string and must be:
 *  - 7-characters starts with "#" symbol ('#ffffff')
 *  - or 6-characters without "#" symbol ('ffffff')
 *  - or 4-characters starts with "#" symbol ('#fff')
 *  - or 3-characters without "#" symbol ('fff')
 *
 * @function { color: string => string } convertHexToRgb
 * @return { string } returns RGB color string or empty string
 */
export const convertHexToRgb = (color: string): string => {
    const errMessage = `
    Something went wrong while working with colors...
    
    Make sure the colors provided to the "PieDonutChart" meet the following requirements:
    
    Color must be only HEX string and must be 
    7-characters starts with "#" symbol ('#ffffff')
    or 6-characters without "#" symbol ('ffffff')
    or 4-characters starts with "#" symbol ('#fff')
    or 3-characters without "#" symbol ('fff')
    
    - - - - - - - - -
    
    Error in: "convertHexToRgb" function
    Received value: ${color}
  `;

    if (
        !color
        || typeof color !== 'string'
        || color.length < 3
        || color.length > 7
    ) {
        console.error(errMessage);
        return '';
    }

    const replacer = (...args: string[]) => {
        const [
            _,
            r,
            g,
            b,
        ] = args;

        return '' + r + r + g + g + b + b;
    };

    const rgbHexArr = color
        ?.replace(HEX_REG_EXP, replacer)
        .match(/.{2}/g)
        ?.map(x => parseInt(x, 16));

    /**
     * "HEX_REG_EXP.test" is here to create more strong tests
     */
    if (rgbHexArr && Array.isArray(rgbHexArr) && HEX_REG_EXP.test(color)) {
        return `rgb(${rgbHexArr[0]}, ${rgbHexArr[1]}, ${rgbHexArr[2]})`;
    }

    console.error(errMessage);
    return '';
};

我正在使用Jest进行测试

color.spec.ts

describe('function "convertHexToRgb"', () => {
    it('returns a valid RGB with the provided 3-digit HEX color: [color = \'fff\']', () => {
        expect.assertions(2);

        const { consoleErrorMocked }  = mockConsole();
        const rgb = convertHexToRgb('fff');

        expect(RGB_REG_EXP.test(rgb)).toBeTruthy();
        expect(consoleErrorMocked).not.toHaveBeenCalled();
    });

    it('returns a valid RGB with the provided 3-digit HEX color with hash symbol: [color = \'#fff\']', () => {
        expect.assertions(2);

        const { consoleErrorMocked }  = mockConsole();
        const rgb = convertHexToRgb('#fff');

        expect(RGB_REG_EXP.test(rgb)).toBeTruthy();
        expect(consoleErrorMocked).not.toHaveBeenCalled();
    });

    it('returns a valid RGB with the provided 6-digit HEX color: [color = \'ffffff\']', () => {
        expect.assertions(2);

        const { consoleErrorMocked }  = mockConsole();
        const rgb = convertHexToRgb('ffffff');

        expect(RGB_REG_EXP.test(rgb)).toBeTruthy();
        expect(consoleErrorMocked).not.toHaveBeenCalled();
    });

    it('returns a valid RGB with the provided 6-digit HEX color with the hash symbol: [color = \'#ffffff\']', () => {
        expect.assertions(2);

        const { consoleErrorMocked }  = mockConsole();
        const rgb = convertHexToRgb(TEST_COLOR);

        expect(RGB_REG_EXP.test(rgb)).toBeTruthy();
        expect(consoleErrorMocked).not.toHaveBeenCalled();
    });

    it('returns an empty string when the provided value is not a string: [color = 1234]', () => {
        expect.assertions(2);

        const { consoleErrorMocked }  = mockConsole();

        // @ts-ignore
        const rgb = convertHexToRgb(1234);

        expect(rgb).toBe('');
        expect(consoleErrorMocked).toHaveBeenCalledTimes(1);
    });

    it('returns an empty string when the provided color is too short: [color = \'FF\']', () => {
        expect.assertions(2);

        const { consoleErrorMocked }  = mockConsole();

        const rgb = convertHexToRgb('FF');

        expect(rgb).toBe('');
        expect(consoleErrorMocked).toHaveBeenCalledTimes(1);
    });

    it('returns an empty string when the provided color is too long: [color = \'#fffffff\']', () => {
        expect.assertions(2);

        const { consoleErrorMocked }  = mockConsole();

        const rgb = convertHexToRgb('#fffffff');

        expect(rgb).toBe('');
        expect(consoleErrorMocked).toHaveBeenCalledTimes(1);
    });

    it('returns an empty string when the provided value is looks like HEX color string but has invalid symbols: [color = \'#fffffp\']', () => {
        expect.assertions(2);

        const { consoleErrorMocked }  = mockConsole();
        const rgb = convertHexToRgb('#fffffp');

        expect(rgb).toBe('');
        expect(consoleErrorMocked).toHaveBeenCalledTimes(1);
    });

    it('returns an empty string when the provided value is invalid: [color = \'*\']', () => {
        expect.assertions(2);

        const { consoleErrorMocked }  = mockConsole();

        const rgb = convertHexToRgb('*');

        expect(rgb).toBe('');
        expect(consoleErrorMocked).toHaveBeenCalledTimes(1);
    });

    it('returns an empty string when the provided value is undefined: [color = undefined]', () => {
        expect.assertions(2);

        const { consoleErrorMocked }  = mockConsole();

        // @ts-ignore
        const rgb = convertHexToRgb(undefined);

        expect(rgb).toBe('');
        expect(consoleErrorMocked).toHaveBeenCalledTimes(1);
    });
});

测试结果:

function "convertHexToRgb"
    √ returns a valid RGB with the provided 3-digit HEX color: [color = 'fff']
    √ returns a valid RGB with the provided 3-digit HEX color with hash symbol: [color = '#fff']
    √ returns a valid RGB with the provided 6-digit HEX color: [color = 'ffffff']
    √ returns a valid RGB with the provided 6-digit HEX color with the hash symbol: [color = '#ffffff']
    √ returns an empty string when the provided value is not a string: [color = 1234]
    √ returns an empty string when the provided color is too short: [color = 'FF']
    √ returns an empty string when the provided color is too long: [color = '#fffffff']
    √ returns an empty string when the provided value is looks like HEX color string but has invalid symbols: [color = '#fffffp']
    √ returns an empty string when the provided value is invalid: [color = '*']
    √ returns an empty string when the provided value is undefined: [color = undefined]

和mockConsole:

export const mockConsole = () => {
  const consoleError = jest.spyOn(console, 'error').mockImplementationOnce(() => undefined);
  return { consoleError };
};

My example =) color: { toHex: function(num){ var str = num.toString(16); return (str.length<6?'#00'+str:'#'+str); }, toNum: function(hex){ return parseInt(hex.replace('#',''), 16); }, rgbToHex: function(color) { color = color.replace(/\s/g,""); var aRGB = color.match(/^rgb\((\d{1,3}[%]?),(\d{1,3}[%]?),(\d{1,3}[%]?)\)$/i); if(aRGB) { color = ''; for (var i=1; i<=3; i++) color += Math.round((aRGB[i][aRGB[i].length-1]=="%"?2.55:1)*parseInt(aRGB[i])).toString(16).replace(/^(.)$/,'0$1'); } else color = color.replace(/^#?([\da-f])([\da-f])([\da-f])$/i, '$1$1$2$2$3$3'); return '#'+color; }

对于直接从jQuery转换，您可以尝试:

  function rgbToHex(color) {
    var bg = color.match(/^rgb\((\d+),\s*(\d+),\s*(\d+)\)$/);
    function hex(x) {
      return ("0" + parseInt(x).toString(16)).slice(-2);
    }
    return     "#" + hex(bg[1]) + hex(bg[2]) + hex(bg[3]);
  }

  rgbToHex($('.col-tab-bar .col-tab span').css('color'))