rainbow script

x = document.getElementsByTagName('p');
for (i = 0; i < x.length; i++) {
    x[i].innerHTML = x[i].innerHTML.replace(/([“”’'"\u00BF-\u1FFF\u2C00-\uD7FF\w]+)/g, '<span class="flicker">$1</span>');
}
var interID;

flickerers = document.getElementsByClassName('flicker');
for (i = 0; i < flickerers.length; i++) {
    flickerers[i].addEventListener("mouseover", function (e) {
        var proxy = this
        interID = setInterval(function () {
            switch (proxy.style.backgroundColor) {
                case 'transparent':
                case 'purple':
                    proxy.style.backgroundColor = 'red';
                    break;
                case 'red':
                    proxy.style.backgroundColor = 'orange';
                    break;
                case 'orange':
                    proxy.style.backgroundColor = 'yellow';
                    break;
                case 'yellow':
                    proxy.style.backgroundColor = 'green';
                    break;
                case 'green':
                    proxy.style.backgroundColor = 'blue';
                    break;
                case 'blue':
                    proxy.style.backgroundColor = 'purple';
                    break;
                default:
                    proxy.style.backgroundColor = 'red';
            }
        }, 50);
    });

    flickerers[i].addEventListener("mouseout", function () {
        clearInterval(interID);
    });
}