There's a hidden secret to this Rainbow Cheesecake recipe. A surprise. And no, the surprise isn't the awesome rainbow layers that appear on each slice of cake. The surprise is that it's the best cheesecake you'll ever eat. Beyond being beautiful, it's silky, smooth, light, and tasty all at the same time. It's the kind of cheesecake that needs no topping. The downside of making this amazing cheesecake from scratch, however, is that it takes roughly 8 hours to make. So plan accordingly! You’ll need a springform pan, which is the only way to get the cake to mold correctly. You also need to make sure your springform pan is waterproof because you need to actually bake this cake in a water bath. Have no fear though. This isn't hard. Just take a few layers of foil and carefully wrap it around the pan in both directions. Fold it carefully all around the edges until it fits snugly against the pan. (Be careful not to rip the foil.) Now, of course, you don't have to do the whole rainbow thing. If you leave it out you'll still be left with a very awesome standard-colored cheesecake that will wow your guests. And yes, I realize that the rainbow actually has seven colors, but for this dish it's pretty impossible to tell the difference between violet and indigo. So six will do! Once you have your colors mixed, pour them into the prepared pan with the crust in a logical order, which for me was: red, orange, yellow, green, blue, purple. The trick is to pour each color right in the center of the dish. This will cause them to spread out evenly so each slice has all the layers! When it's done baking, the goal is to cool it down as slowly as possible so the cake doesn't crack a lot. The best way to do this is to turn off the oven, crack the door a bit, and let it cool in the water bath inside the oven for about an hour. When it comes out, remove it from the water bath, cover it loosely with foil and store it in the fridge for at least 4 hours.