This is a Work in Progress, and as such the description may not accurately describe the entire list.
A post-rotation list of my Dega Divine (Control Variant) list.
This deck plays really midrange-y and at times can play either really aggresive or control-y, but is meant to play with a lot of removal and sticking a single creature to eventually win the game.
3 Color in Theros: It's doable, really, you just have to anticipate and build your manabase around the deck or the deck around a plausible manabase, it's no longer manaisn'taproblemI'llplaythis.dec, it requires building something that works for your deck, scrylands work here because it plays slower, every land in the deck is able to cast Boros Reckoner which is important, which is why it doesn't run any Swamp even though it is mostly black orientated or B/R/w, hence the Rakdos Guildgate at a 4-of
Card Selection:
Thoughtseize: Provides information and early removal on a 1-for-1 basis. Basically eliminating a threat before it hits the field. Can be used to force a counter, but eventually becomes a bad top-deck later game is why it has been dropped to 3.
Dreadbore: Is run as a 4-of because it hits any creature, and is not entirely dead against control (they usually run planeswalkers) it is preferred to Hero's Downfall due to the less color intensity of BB even at the cost of instant speed this will typically play on T3 anyways.
Doom Blade: Cheap, fast removal that get's replaced by Dark Betrayal from the side. Unfortunately it is dead to both B based creature decks and most control lists; may be changed based on how the local meta turns out.
Magma Jet: Shock+Scry, love it. It always scrys and can kill a creature or just do 2 damage, the main reason it is run is due to scry, but extra removal is fine.
Anger of the Gods: Plays well against things like Chandra's Phoenix and other small red creatures, it hits anything Elspeth, Sun's Champion can't hit, and only kills my Boros Reckoners which still lets me hit x/4-6 or even dome them for 3, so not a bad trade-off, typically played t4.
Hero's Downfall: As a singleton I have not had problems casting it and it also hits planeswalkers so there's a plus. Unrestricted Removal at instant speed is good; better Murder.
Boros Reckoner: The aggro wall and the guy who can trade with anything up to x/6's, is a phenomenal blocker and aggressor especially with Whip of Erebos.
Read the Bones: Allows you to manipulate up to 4 cards on top of your deck, getting you to your answers or threats as the game-state calls for. Filters lands to find more gas. Filters removal to find more gas, whatever you need. Plus Draw 2, usually played later in the game with removal mana up or a solid boardstate, sometimes to find an out early game though.
Desecration Demon: Big Beater coupled with removal to keep a small board, allows a large threat without over-extending, dangerous Whip of Erebos target, and easy to cast on t4-5.
Whip of Erebos: Lifelink to everything to help even out damage taken from shocks, Thoughtseize, Read the Bones and other creatures. Great interaction with Obzedat, Ghost Council. Allows for some CA against control who removes our creatures, and is an extra 4-drop.
Blood Baron of Vizkopa: Hard to remove body with lifelink to boot. Can win a lot of aggro, B/x, B/x/x, W/x, or W/x/x games on his own and is easy to cast at 5.
Obzedat, Ghost Council: While WWBB is hard to get to, he really isn't the first threat this deck wants to play anyways, he is the last play if other threats are available to bait their removal/Counters. The deck maximizes W/B lands to help support the cost and scry allows us to find the colors we may need if that is a problem. Overall a good card in that it dodges Doom Blade, Ultimate Price, any sorcery speed removal, and can win the game without ever attacking.
Stormbreath Dragon: Pro-White lets us block opposing Blood Baron of Vizkopas, dodge any W/x Removal (Warleader's Helix, Spear of Heliod, Selesnya Charm, etc). Walls any W or W/x creaturs (Archangel of Thune other Obzedat, Ghost Councils). And is a haste-y dragon with the ability to grow later in the game.
Elspeth, Sun's Champion: Board-wipe, gums up the ground, and is one of the only cards that can come back from a losing game and win it on its own. At worst it's 3 1/1's for 6.