Now, maybe if you know you are playing against a flying deck, you could build around Ifh-Biff Efreet
Since you need to check for color identity and not just a cards color, cards that are blue or black and have other mana symbols in their effects cant be played in a Yuriko deck
Hobgoblin Bandit Lord is hovering around $4 a card now, but the more people get to play with it (and the more they realize it can help set up an alternate win condition in goblin commander decks), the more they should be able to charge for it
Dualcaster Mage is one of the most played red creatures in EDH
I mentioned Peregrine Drake before, which goes infinite with Deadeye Navigator
Green, on the other hand, isnt a primary color for any of the classes but is the only color to have access to all four classes