Welcome to the forum! Color is such a personal choice. I think the car looks great in any color. I personally love Racing Yellow, but it does scream midlife crisis. Most of the bright colors sort of do. Doesn't mean I don't love them anyway. When I started research on the 718 I was sold on Racing Yellow. Now, I'm leaning towards Night Blue. That's only because I'm thinking I want go in a "classier" direction. By the time I'm ready to order (over a year away) there's no telling what I'll want then. When I pick a color I want something that I'll be ok looking at everyday for 3-5 years.
You can't go wrong with any of the three. If bold is what you want, I don't think the Rhodium gets that. I think it falls into the "classier" category. Of the three, I'd probably get the Miami Blue. On a recent trip to the northeast I passed one on a showroom floor. First one I've seen live. It's pretty. The fact that my current BMW 2 series is Valencia Orange would keep me from getting another orange car next even though I love the Lava Orange, also.
What color interior are you going with?