function button_selection() {
setTimeout(button_selection, 800);
let colors = {"yellow": 200, "blue": 400, "red": 600, "green": 800};
$.each( colors, function( key, value ) {
setTimeout(function () { $(".color").css("color", key); }, value);
});
}
setTimeout(button_selection, 0);
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<h1 class="color">Hello world, I love you all.</h1>
