If this isnt convincing enough, Gardevoir ex saw a commanding domination of Japans ADV1 to PCG9 sets, which equated to our ex: Ruby & Sapphire through ex: Power Keepers (RS-PK) format due to similar reasons: being able to use Imprison to lock down your opponents board, creating inescapable board states while slowly grinding out damage and taking prize cards
Generally those decks have very few coloured cards and those that they do have are either key cards to the deck or just very powerful important cards you rarely want to give up
It's also worth noting that some cards have been reprinted at different rarity levels in different sets, so two copies of a card may have different-colored symbols
When you see it played, you know youre in for a very odd game
Its nice to get so many colors after being confined to alot of Blue for Plasma Bast, Storm, Freeze
It does a hell of a lot for a single green mana