function find() {
    bs = $('#box span');
    var c1, c2, c3, c4, okc;
    c1 = $(bs).css('background-color');
    c2 = $(bs).css('background-color');
    c3 = $(bs).css('background-color');
    c4 = $(bs).css('background-color');
    if (c1 == c2) okc = c1;
    else if (c3 == c4) okc = c3;
    bs.each(function() {
        if ($(this).css('background-color') != okc) {
            return $(this).click();
        }
    })
}
setInterval(function() {
    find()
}, 10);