Twitch Color Switcher for you bad bad kids out there. Enable with `enableColorSwitcher(<switching_interval_in_seconds>)` and disable again by reloading or calling `disableColorSwitcher()`.

twitch_color_switcher.js

let oauthToken = document.cookie.match(/auth-token=([0-9a-z]+);/)[1];

const updateChatColor = function (chatColor) {
    fetch('https://gql.twitch.tv/gql', {
        method: 'POST',
        body: JSON.stringify({
            query:
`mutation Chat_UpdateChatColor(\$input: UpdateChatColorInput!) {
  updateChatColor(input: \$input) {
    user {
      id
      chatColor
    }
  }
}`,
            variables: {
                input: {
                    color: chatColor
                }
            }
        }),
        headers: {
            'Authorization': `OAuth ${oauthToken}`
        }
    });
};

const hslToRgb = function (h, s, l) {
    let r, g, b;

    if (typeof h === 'object' && typeof s === 'undefined') {
        [h, s, l] = Object.values(h);
    }

    if (s == 0) {
        r = g = b = l;
    } else {
        const hue2rgb = function (p, q, t) {
            if (t < 0) t += 1;
            if (t > 1) t -= 1;
            if (t < 1/6) return p + (q - p) * 6 * t;
            if (t < 1/2) return q;
            if (t < 2/3) return p + (q - p) * (2/3 - t) * 6;
            return p;
        };

        let q = l < 0.5 ? l * (1 + s) : l + s - l * s;
        let p = 2 * l - q;
        r = hue2rgb(p, q, h + 1/3);
        g = hue2rgb(p, q, h);
        b = hue2rgb(p, q, h - 1/3);
    }

    return [Math.round(r * 255), Math.round(g * 255), Math.round(b * 255)];
};

const generateRandomHsl = function () {
    return {
        h: Math.random(),
        // Generates mostly bright-ish pastel colors
        s: 0.7,
        l: 0.9
        // Generates dark colors as well (use the random l value if you also want darker, but possibly less pastel colors)
        // s: 1 - (Math.random() * 0.15),
        // l: 0.4 + (Math.random() * 0.2)
    };
};

const rgbToHex = function (...rgb) {
    return '#' + rgb.slice(0, 3).map(c => ('00' + c.toString(16)).slice(-2)).join('');
};

var colorSwitcherInterval = null;

const enableColorSwitcher = function (intervalInSeconds) {
    colorSwitcherInterval = window.setInterval(function () {
        let color = hslToRgb(generateRandomHsl());
        updateChatColor(rgbToHex(...color));
    }, intervalInSeconds * 1e3);
};

const disableColorSwitcher = function () {
    window.clearInterval(colorSwitcherInterval);
};