Any three color combination can work well depending on the precise mix of cards which show up for you
While players have certainly found ways to make powerful decks - with some popular meta decks becoming mainstays in tournaments - the community generally finds ways to combat these and develop counter-strategies, without the need for any cards to be banned from play yet
From Midgard to Modern: Why (Almost) Every MTG Format is Impacted Are you playing with the new Magic: The Gathering Final Fantasy cards
The clause allowing Ifrit as a red creature to deal damage to a creature with protection from red became a static ability that's always true, meaning he can deal damage in combat if they blocked him
(To investigate, create a Clue token
Satya, Aetherflux Genius headlines MTG Modern Horizons 3s Creative Energy pre-con deck, and this talented Kaladesh Artificer is helping to bring that planes Energy mechanic back in a big way