I applied an odd/even class to the fc-agenda-slot tr\'s, but the problem is the left/right \"cell\" border is on the fc-agenda-days table which is below, so it\'s not shown when
Kind of late, but add this to your CSS
.fc-agenda-slots tr.d1 td {
background-color: rgba(79, 129, 128, .2); color: black;
}
and this in your JS to execute right after you render your calendar.
$("table tr").each(function () {
var i = $("table tr").index($(this));
if (i % 4 == 1 || i % 4 == 2)
$(this).addClass("d1");
});
btw this is only for week view.