49 cards where the cards aren’t reprints and the card is tagged “colourless-matters”

Mystic Forge (Core Set 2020 #233)
Ugin, the Ineffable (War of the Spark #2)
Forsaken Monument (Zendikar Rising #244)
Liberator, Urza's Battlethopter (The Brothers' War #237)
Shrine of the Forsaken Gods (Battle for Zendikar #245)
Tomb of the Spirit Dragon (Khans of Tarkir #245)
Conduit of Ruin (Battle for Zendikar #4)
Eldrazi Temple (Rise of the Eldrazi #227)
Sanctum of Ugin (Battle for Zendikar #242)
Titan's Presence (Battle for Zendikar #14)
Eye of Ugin (Worldwake #136)
Darksteel Monolith (Commander Masters #743)
Zhulodok, Void Gorger (Commander Masters #704)
Skittering Cicada (Commander Masters #717)
Calamity of the Titans (Commander Masters #713)
Ugin's Mastery (Commander Masters #718)
Abstruse Archaic (Commander Masters #712)
Ruins of Oran-Rief (Oath of the Gatewatch #176)
Eldrazi Mimic (Oath of the Gatewatch #2)
Gruesome Slaughter (Battle for Zendikar #9)
Nettle Drone (Battle for Zendikar #131)
Herald of Kozilek (Battle for Zendikar #205)
Omarthis, Ghostfire Initiate (Commander Masters #708)
Vannifar, Evolved Enigma (Murders at Karlov Manor #241)
Spreading Plague (Invasion #125)
Ancient Stirrings (Rise of the Eldrazi #174)
Ruination Guide (Battle for Zendikar #64)
Forerunner of Slaughter (Battle for Zendikar #204)
Flayer Drone (Oath of the Gatewatch #148)
Ghostfire Blade (Khans of Tarkir #220)
Vile Aggregate (Battle for Zendikar #137)
Tide Drifter (Battle for Zendikar #67)
Thought Harvester (Oath of the Gatewatch #48)
Cultivator Drone (Oath of the Gatewatch #42)
Barrage Tyrant (Battle for Zendikar #127)
Molten Nursery (Battle for Zendikar #130)
It That Heralds the End (Modern Horizons 3 #9)
Dominator Drone (Battle for Zendikar #92)
Swarm Surge (Battle for Zendikar #100)
Dust Stalker (Battle for Zendikar #202)
Infernal Reckoning (Core Set 2019 #102)
Ugin's Construct (Fate Reforged #164)
Kozilek's Sentinel (Battle for Zendikar #129)
Eldrazi Aggressor (Oath of the Gatewatch #95)
Sky Scourer (Oath of the Gatewatch #78)
Reaver Drone (Oath of the Gatewatch #76)
Grizzled Angler // Grisly Anglerfish (Eldritch Moon #63)
Grizzled Angler // Grisly Anglerfish (Eldritch Moon #63)
Skitterskin (Battle for Zendikar #97)
Ugin's Labyrinth (Modern Horizons 3 #233)

Though this query has ended, its relics still slumber in New Argive.