The Pokémon Company's 30th anniversary trading card set is set to include the rarest cards ever produced for sale, according to claims from an insider at printing partner Millennium Print Group. Fans had speculated for months about mysterious monochromatic "RGB" Mew cards spotted in early packs, unable to confirm whether they were genuine, but a wider spread of sightings has now established their authenticity. The reveal matters because it confirms The Pokémon Company deliberately concealed part of the set's contents and is actively guarding the surprise ahead of release.

Three colour variants of a chase Mew card — red, blue and green, referencing the original Pokémon games — have surfaced so far, with a matching Mewtwo variant expected given its place in the set's new "Future Rare" category. The alleged insider told a Pokémon influencer, The Card Science, that RGB cards appear in roughly one in 20,000 packs, far scarcer than the one-in-1,260 odds for a golden Mega Hyper Rare card in recent sets. While ultra-rare promotional cards such as the roughly 40 existing Pikachu Illustrator cards remain scarcer overall, RGB cards are expected to be the hardest pull among cards available to ordinary buyers through standard packs.