If no one else is taking green, you can go into it to get some amazing fat (yay Verdant Force!)
Otherwise go with White, Black, or Red (or some combination of those)
Soltari Monk/Priest automatically win the game if they have enough turns, as almost nothing can stop them directly if you have other creatures on the board waiting for an Edict. Cataclysm is insane if you get to keep a shadow creature.
Dauthi Warlord and Ghoul will get monstrously powerful if your opponent doesn't have a blocker available early and you have some graveyard recursion. Living Death, Edict, and Slaughter are all stupidly powerful in most any circumstance.
Red's buyback burn is nothing short of unfair in most cases. Red is going to go to the head in most cases, as there are a lot of common shadow creatures that are in the common slot. If your opponent plays a Soltari Priest, unload everything you have at their head, as you are going to die to the stupid thing eventually.
Blue's Thalakos are generally weaker than the Dauthi and Soltari, BUT bear in mind that the B and W shadows are basically designed to fight each other. Thalakos creatures are generally not effected as heavily or at all by the various abilities of the others (Horror, Monk, etc.) However, you don't have as many shadow creatures nor do you have any way to outright kill your opponents' outside of combat, so play defensively. Finally, this should go without saying, but I'll repeat it here: DRAFT THE SILVER WYVERN. That should be obvious, but never forget it. That beast is just crazy when the board fills up later on.
