I think this would require someone to comb through a bunch of users' palettes manually to determine what is "beautiful" to them? Since there's no real way to favorite people's palettes the way there is with entries that would indicate to the site what a "good/well acclaimed palette" is. Even assuming the person who's picking the palettes has good taste, that's a lot of work to go hunting for palettes, unless you appointed multiple people, at which point the likelihood for poor taste picks increases unless you agree as a group, and now it's turned into a whole extra human process that would take a noticeable amount of energy from people.
Or, just have it pick a random one and then the palette of the day can be anything from perfection to the most painful thing imaginable. I also struggle to see how you would showcase said palette of the day without some form of overwriting the home page, so you'd really want to make sure it's actually a good palette to ensure that first-time visitors don't get turned off of the site by something peculiar.
Fun-sounding in concept, but pretty painful-sounding in execution.