This data is collected from the articles deck lists in EDH Chamber.
Dragons, alongside Goblins, are reds primary creature types. Dragons are reds strongest creatures and most of the expansions have some kind of red dragon in them. As dragons are expensive to cast, dragon tribal decks run multiple cost reduction effects and have ways to cheat the expensive dragons on the battlefield.
Angels are one of Magics strongest creatures, and are comparable to Dragons and Demons. Angels are strong, flying creatures, with often static abilities or strong ETB triggers.
Cheating permanents to the battlefield is available in every colours. How the permanents are cheated into play depends on the colours available, eg black uses reanimation from the battlefield and red uses sneaking, meaning the permanent will be sacced in the end of the turn.