window.onload = function() {
    var num = 8;
    var time = new Date();
    var color = new Array(num);
    color[0] = "#09c";
    color[1] = "#0c9";
    color[2] = "#90c";
    color[3] = "#9f3";
    color[4] = "#c09";
    color[5] = "#fc0";
    color[6] = "#c03"
    color[7] = "white"
    document.getElementById('wrap').style.backgroundColor = color[(time.getHours() % num)];
}