Free Discord Custom Theme

let root = document.getElementsByTagName("html")[0];
let className = "custom-theme-background";

const options = {
  attributes: true
}

function callback(mutationList, observer) {
  mutationList.forEach(function(mutation) {
    if (mutation.type === 'attributes' && mutation.attributeName === 'class') {
        if (root.classList.contains(className)) return;
        document.getElementsByTagName("html")[0].classList.add(className)

        var head = document.head || document.getElementsByTagName('head')[0],
            style = document.createElement('style');

        var css = '.custom-theme-background {--custom-theme-background: linear-gradient(128.92deg, var(--bg-gradient-chroma-glow-1) 3.94%, var(--bg-gradient-chroma-glow-2) 26.1%, var(--bg-gradient-chroma-glow-3) 39.82%, var(--bg-gradient-chroma-glow-4) 56.89%, var(--bg-gradient-chroma-glow-5) 76.45%);}';

        head.appendChild(style);
        style.appendChild(document.createTextNode(css));
    }
  })
}

const observer = new MutationObserver(callback)
observer.observe(root, options)