The three options are gray, yellow, and turquoise. What color do you like best? I like the yellow and the turquoise. Since Im considering the Lite for ACNH, I'm wondering if the yellow would be too bright and loud for the colors in the game. So I might do turquoise, but yellow is so fun.
Don't forget that there's also the Pokemon Zacian & Zamazenta Edition due out in November, too, so there's a fourth colourway for your consideration, as well.
Anyway, I have a yellow one, and I absolutely love how it looks. I can tell you that the brightness of the casing doesn't affect viewing the screen nor does it interfere with any in-game colours at all.
Of course, for all we know, they might reveal an Animal Crossing edition closer to the launch of ACNH, too, so if you're not planning on picking one up ahead of time to play other games in the meantime, maybe it'd be worth waiting to see if they do that?
Update! I got the yellow Lite and its so bright and happy! It makes me happy just to look at. I was having a hard time choosing between turquoise and yellow, and I would have really expected myself to choose turquoise since that's one of my favorite colors, but there was something about the yellow one that kept pulling me back.