I was stratosphere all the way but now I'm biased. AZ contrasts the gunmetal wheels and black trim so well!! And when the sun hits it just right, pure pearl.
Man the A90 has had a few really cool colors and I feel like the current palette is worse than ever. Downshift was such a classy blue, Phantom was maybe my favorite paint I've ever seen on a car (turbulence was also awesome looking), & Nitro is discontinued.
I do think that Stratosphere and Nocturnal look best with the new wheels out of the current options.
Black always looks the best, problem is that its absolutely impossible to keep that mirror/glass finish if you drive at all. I am blown away with Absolute Zero in person (and love mine) but would trade in a second for the CU Grey