You can play a three color deck in this format, especially a wedge, but it's by no means necessary to be competitive. Treat the draft like any other core set draft: start by grabbing powerful cards and remaining open until you identify the appropriate archetype for your seat. The 2-color archetypes are - as usual - characterized by the 10 gold uncommons:
Ironroot Warlord,
Empyrean Eagle,
Tomebound Lich,
Ogre Siegebreaker,
Creeping Trailblazer,
Corpse Knight,
Lightning Stormkin,
Moldervine Reclamation,
Skyknight, and
Risen Reef.
No matter which way you go the format is pretty "classic": you should either be looking to curve 1-drop, 2-drop, 3-drop or else know for sure you have play against someone so curving out.
Wait. 1-drop?
Yeah! There are a number of relevant aggro ones in the set. White has
Loyal Pegasus, a 2/1 flier for one. Red has
Scorch Spitter, a 1/1 that deals an extra 1 to face when it attacks and has a key creature type (elemental). Blue has the flying 1/1
Faeire Miscreant which I know doesn't sound like much but is justifiably playable if its drafted with a couple of friends. Green has 1/1 deathtouch
Sedge Scorpion which is made relevant by defensive applications and Prey Upon. Black is the scariest by far with 1/1 deathtouch lifelink
Vampire of the Dire Moon and
Knight of the Ebon Legion, thankfully an uncommon and a rare respectively but still the kind of thing you benefit from being prepared for.
You can't assume big-booty blockers are going to save you from aggressive opponents. White and green have cheap little dedicated blockers - these do nothing. Blue's 1/6 for four isn't much better. Evasion is common - white, blue and even red are rife with fliers; red has
Goblin Smuggler to sneak through a host of little red attackers which become *much* bigger once combat has begun; and there's at least one creature with protection from the color of whatever blocker you're fielding. There's also enough removal in the set for aggro opponents to push through a limp defense.
If you're not attacking, you need to rely on removal of your own.
Murder is at common, and so are a bunch of color hosers and conditional removal spells which all function basically as Murder when you bring them in post-board.
Prey upon,
Disfigure,
Chandra's Outrage,
Agonizing Siphon and a few other options besides round out an impressive removal suite you'll want to leverage.
Flame Sweep, an uncommon conditional sweeper, is strong against the *particularly* degenerate approaches to aggro.
If things stabilize then you get value in this format from cards that synergize well with themselves. Some of these are obvious -
Faeire Miscreant,
Undead Servant, etc. - but look at
Lavakin Brawler,
Empyrean Eagle,
Risen Reaf, or the previously mentioned
Loyal Pegasus. These are all fun in multiples and let you get value out of
Pattern Matcher. It's a straightforward way to get synergy but it's all you really need in this set.