You're not that far off... For a period of time, Lucky the Leprechaun got replaced with Waldo the Wizard only in New England before Lucky took control of the whole franchise once again.
Oh, and red balloons were added at the same point as the horseshoes. Then because of the commercial where Lucky's new red balloon hot air balloon got punctured dropping him into the mercolony of Atlantis, he was able to rise back into the regular world thanks to the combined star balloons.
After that... Well, they got rid of the yellow moons and blue diamonds to bring in the blue moons. Then the tri-beam rainbows, yellow and orange coin-filled pots of gold, the crystal balls, leprechaun hats with the clovers, shooting stars, magic mirror to be replaced by the hourglass to be retired and replaced with the unicorn last year.
The reason I thought the unicorns might be mainly yellow is because that's the one color band of the rainbow that's been in most flux regarding its charm from having one to being unrepresented until the next one was decided upon. Who knows, maybe the gravity-controlling moon is a big round yellow full moon.