31 cards where the card types include “artifact” and the number of colors ≥ 3

Arsenal Thresher (Planechase #96)
Ashad, the Lone Cyberman (Doctor Who #113)
Breya, Etherium Shaper (Modern Horizons 3 #289)
Cult of Skaro (Doctor Who #117)
Darksteel Hydra (Alchemy: Phyrexia #20)
Davros, Dalek Creator (Doctor Who #1)
Enigma Sphinx (Commander 2018 #178)
Esper Sojourners (Alara Reborn #107)
Esper Stormblade (Alara Reborn #132)
Etherwrought Page (Alara Reborn #108)
Liberty Prime, Recharged (Fallout #5)
Magister Sphinx (Double Masters 2022 #247)
Megatron, Tyrant // Megatron, Destructive Force (Transformers #12)
Megatron, Tyrant // Megatron, Destructive Force (Transformers #12)
Mr. House, President and CEO (Fallout #7)
Optimus Prime, Hero // Optimus Prime, Autobot Leader (Transformers #13)
Optimus Prime, Hero // Optimus Prime, Autobot Leader (Transformers #13)
Reaper King (Shadowmoor #260)
Sen Triplets (Double Masters #218)
Sharuum the Hegemon (Double Masters #219)
Sludge Strider (Planechase #95)
Soundwave, Sonic Spy // Soundwave, Superior Captain (Transformers #14)
Soundwave, Sonic Spy // Soundwave, Superior Captain (Transformers #14)
Sphinx of the Guildpact (Double Masters #290)
Sphinx of the Steel Wind (Eternal Masters #207)
Sphinx Sovereign (Shards of Alara #196)
Tetzin, Gnome Champion // The Golden-Gear Colossus (The Lost Caverns of Ixalan Commander #13)
Tetzin, Gnome Champion // The Golden-Gear Colossus (The Lost Caverns of Ixalan Commander #13)
The Master, Transcendent (Fallout #6)
Thopter Foundry (Double Masters #222)
Tower Gargoyle (Double Masters 2022 #288)
Transguild Courier (Dominaria United Commander #194)
Ultra Magnus, Tactician // Ultra Magnus, Armored Carrier (Transformers #15)
Ultra Magnus, Tactician // Ultra Magnus, Armored Carrier (Transformers #15)
Unscythe, Killer of Kings (Alara Reborn #114)
Windwright Mage (Shards of Alara #208)

The orcs’ banner sends a clear message: “You've reached the end of this search.”