I am looking forward to all those multicolored and hybrid cards that will be issued as part of the Return to Ravnica (RTR) Block. Looking back at all of the modern design multicolored and hybrid cards is interesting. Here is a multicolored card. Hybrid cards allow for an OR between two colors.
Here are the sets that account for the largest number of multicolored and hybrid cards.
And here are sets with fewer quantities of these cards. The Innistrad block sets are in this table.
Looking at the various color combinations the guilds are well represented historically because two blocks (Shards of Alara and Ravnica: City of Guilds) were designed with many multicolored cards. Ravnica: City of Guilds naturally covers the guilds with balance. Interestingly, Shadowmoor and Eventide have many two-color cards that can be used for guild decks.
The other sets have a random selection of guilds and shards.
The balance between hybrid and multicolored is not the same for every guild. The total number of cards for each two-color combination is not even because except for the Ravica block, the other sets were not designed to have this type of balance. A two-color card not in the Ravnica block is not playing into the guild scheme.
Or for every Shard or four and five color card.
Here are the cards by type for the ten guilds.
Here are the legendary creatures and planeswalkers.