With the conclusion of the Magic the Gathering Mythic V Championship, the standings of the players could be used to rank the quality of decks. Each player had a corresponding deck listed on the Magic the Gathering official website. In the standard card legality, one might wonder which color has the highest chance to yield a win from a deck in the color. In this case, we can look at what the card colors are for each card in the 68 total decks to look for the best color.
As the rank of the deck decreases (closer to 1st in the tournament), the use of black cards as the majority in a deck decreases. This indicates that the current standard legality cards are sufficient to reach the tournament stage, but not good enough to advance very far, around 30th place. However, across all the decks, green is used consistently in a large quantity. This is especially true for decks that are in the top 10.
The largest portion of decks in the top 10 have a high amount of green colored cards, with a mix of other colors. There is two decks that made it very far in the tournament, to 8th and 9th place in the tournament, with a majority red deck. However, the best colored deck, according to the top 5 for the Mythic V Championship would consist mostly of Green, Red, and Blue.
Given the 68 decks used in the tournament, a large quantity used a green majority deck. Coming in second is green-blue decks, where combination cards of green and blue were the majority card color identities in the deck.
Based on these insights, if you were to build a new deck for tournament, with standard card legalities, you should build a tricolor deck with mostly green colored cards, combined with red and blue cards to support the greens.