Slightly off topic, did Magic the Gathering copy holofoil cards from Pokemon
(2025-06-06) The back face of a nonmodal double-faced card usually has a color indicator that defines its color

Giving Them the Answer with New-Sheoldred | Commander | Abe Sargent Commander (1) 1 Sheoldred, the Apocalypse Creatures (23) 1 Burnished Hart 1 Drana, Kalastria Bloodchief 1 Dread Presence 1 Epicure of Blood 1 Erebos, God of the Dead 1 Filth 1 Gray Merchant of Asphodel 1 Kokusho, the Evening Star 1 K'rrik, Son of Yawgmoth 1 Liliana's Shade 1 Murderous Rider 1 Nightmare 1 Nirkana Revenant 1 Noxious Gearhulk 1 Rankle, Master of Pranks 1 Reiver Demon 1 Seizan, Perverter of Truth 1 Solemn Simulacrum 1 Tivash, Gloom Summoner 1 Veinwitch Coven 1 Vilis, Broker of Blood 1 Vito, Thorn of the Dusk Rose 1 Witch of the Moors Planeswalkers (1) 1 Liliana of the Dark Realms Instants (5) 1 Crushing Disappointment 1 Crypt Incursion 1 Defile 1 Hagra Mauling // Hagra Broodpit 1 Tendrils of Corruption Sorceries (12) 1 Bad Deal 1 Chainer's Edict 1 Corrupt 1 Dark Deal 1 Demonic Tutor 1 Exsanguinate 1 Feed the Swarm 1 Infernal Offering 1 Mutilate 1 Nightmare Incursion 1 Peer into the Abyss 1 Syphon Mind Enchantments (5) 1 Black Market Connections 1 Exquisite Blood 1 Greed 1 Sanguine Bond 1 Underworld Dreams I have 59 non lands, one modal land, and then 40 normal lands here

Great fun to kill Precursor Golems with on the other hand
For example, in Urza's Destiny (the set where I was the entire design team), there were two different cycles that explored effects that scaled based on how many cards of a certain color were in your hand
Our final spoiler for the day is from Japanese trading site bigmagic