Abbot of Keral Keep Act on Impulse Alania's Pathmaker Anep, Vizier of Hazoret Archaic's Agony Ardent Dustspeaker Asgardian Inspiration Atsushi, the Blazing Sky Blazing Crescendo Bonehoard Dracosaur Brazen Cannonade Breeches, Eager Pillager Breya's Apprentice Burning Curiosity Cait Sith, Fortune Teller Capricious Sliver Case of the Burning Masks Caves of Chaos Adventurer Chandra, Fire Artisan Chandra, Flameshaper Chandra, Heart of Fire Chandra, Legacy of Fire Chandra, Pyromaster Chaos Channeler Charred Foyer // Warped Space Chase Stein, Runaway Cleon, Merry Champion Clockwork Percussionist Commune with Lava Count on Luck Crimson Caravaneer Crimson Operative Crossover Collaboration Daredevil, Fearless Fighter Dark-Dweller Oracle Diversion Specialist Duchess, Wayward Tavernkeep Ecstatic Beauty Electrostatic Blast Emberheart Challenger Embodiment of Flame Embrace the Unknown End-Blaze Epiphany Endrider Spikespitter Equilibrium Adept Evendo Brushrazer Experimental Synthesizer Fateful Tempest Feldon, Ronom Excavator Fire Giant's Fury Fire-Brained Scheme Fires of Mount Doom Flameskull Galvanic Relay Geistflame Reservoir Gila Courser Glimpse the Impossible Goblin Researcher Grotag Night-Runner Harnesser of Storms Harnfel, Horn of Bounty Haste Magic Headliner Scarlett Hedron Detonator Heroes for Hire Heroes' Hangout Ignite the Future Impossible Inferno Inspired Tinkering Inti, Seneschal of the Sun Irascible Wolverine

This sagas second and third chapters undo some of its damage, so its a little less overwhelming than some of the other options
This is likely the scariest thing you can cheat in, but even if your color identity is mono green, you still have strong choices available, like Ancient Adamantoise and Worldspine Wurm
The adjustment includes conversion to the LAB color space and back to preserve the perceived colors as close as possible