Unless a material has an SPF rating, assume you will get sun/tan/burn. Even with a SPF rating, it's just prolonging your exposure time. Different colors, weaves and types of materials will block more or less of the sun. If the material gets wet (like from your sweat) there's a good chance that whatever protection it was giving will decrease.

I saw an article someplace that did some testing on this and in general some colors of material will offer more protection since it reflects more of the sunlight. But the real differences between colors, assuming the same type of material, were considered insignificant in terms of protecting the skin from cancer causing rays. A light color may give more protection than dark, but if you're going to be out on a two to five hour ride in the middle of the day that difference won't really matter to your skin cells.

Use sunscreen a few minutes before putting your jersey on so it has a chance to set in and not get immediately rubbed off by the jersey.