Utilize the color attribute in HTML elements (e.g. span) in rendered Markdown on GitHub

github_colors.user.js

// ==UserScript==
// @name         GitHub colors
// @namespace    https://logicplace.com/
// @version      1.0
// @description  Support span (and other tags) color on GitHub since I guess it used to work
// @author       Sapphire Becker
// @match        https://github.com/*
// @match        https://gist.github.com/*
// ==/UserScript==

(function() {
    'use strict';

    function update_colors(mutationList, observer) {
        mutationList.forEach((mutation) => {
            switch (mutation.type) {
                case "childList":
                    mutation.addedNodes.forEach((x) => {
                        if (x instanceof Element) {
                            x.querySelectorAll("[color]").forEach((y) => {
                                y.style.color = y.attributes.color.value;
                            });
                        }
                    });
                    break;
                case "attributes":
                    mutation.target.style.color = mutation.target.attributes.color.value;
                    break;
            }
        });
    }

    new MutationObserver(update_colors).observe(
        document.querySelector('.markdown-body'),
        {
            attributes: true,
            attributeFilter: ["color"],
            childList: true,
            subtree: true,
        },
    );

    update_colors([{type: "childList", addedNodes: document.querySelectorAll('.markdown-body')}]);
})();