EVERY year of the Confounding Calendar requires a specific colour palette, and it's one of my favourite things about it, it leads to strikingly pretty games. The other rules also 'control potential themes' too. I prefer to think of it as restrictions breeding serendipity.
Oh my gosh I feel so silly. I saw the color pallete this year had only four colors, and I assumed there couldn’t have been a color pallete last year because of the game Technicolor and Bring Your Pet to School Day. But now that I think about it, while those games had a larger color pallete, it was still a limited set of colors. I just didn’t notice! Oops. Thanks for explaining!