Rise of the Eldrazi is often called battlecruiser Magic. That means that unlike most draft environments where Aggro can play a large part, RoE is about each side building a giant threat and smashing it against each other. There are three main ways this is done:
The Best Defense…
Usually playing lots of creatures with defender isn’t a great way to win. You have to have something to close out the game. In this case you have cards which lets you do damage based on the number of defenders, and overgrown battlement (also a staple in eldrazi decks) to power out a big threat after you clog the ground.
Focus colors: White, Red, Green
Next Level Magic
Levelers are the anti eldrazi. They come out on turn one and two and build up into behemoths.
The best individual levelers are white, red, black, but blue has the important supporting cards that turn the deck into a real threat.
Totem armor tries to overcome the traditional limits of auras, that of making you vulnerable to losing two cards to your opponent one card.
The focus colors here are Green, White, and to a lesser amount, Blue.
But wait, there’s more…
Green and red both have ways to make swarms of little things deadly.
In addition, there’s a cycle of threats from other Zendikar sets. Emeria angel and Avenger of Zendikar give you armies in a can. Obsidian Fireheart brings the burn and the best reminder text in magic. Ob Nixilis, the Fallen gets big while draining you directly. And my favorite, Lorthos, the Tidemaker cares nothing for your blockers.