On a very similar bike (Lynskey Sportive Disc with Di2 hydraulic and Rolf Prima Elan Alpha Disc wheelset) I run the Challenge Strada Bianca. It's marked 30mm but measures 32. Technically it has tread but it's very fine grained and you have to get fairly close to it to notice. I like a little bit of tread in the rain due to all of the pine needles and other road debris in the northwest. While this is my full-fender rain training bike, I like to go fast on it, and the Strada Bianca is a very sporty feeling tire with good high speed handling. They work perfectly at speeds I would be very nervous at with a high-mileage compound like a Marathon. On the flipside they are not cushy feeling, which is something I don't care much about.
There are a few older versions of the Strada Bianca floating around, with and without puncture protection. All of the current versions have PPS2 (double puncture protection) which is marked on the sidewall and you can tell right away by the big bright red strip down the inside of the tire.
They're good in the wet, about the same as the GP 4 Seasons, but not as good (especially "per millimeter of width") as the Michelin Pro4 Grip. However, they have a very smooth and predictable loss of traction so you can drift the rear in the wet, rather than suddenly losing it and going down. They work great at reasonable pressure, I'm 175# and I run 65 rear/60 front in the rain.
The sidewall graphics are red and white so they'll match your bike
If only someone made a great rain-specific tire in 28-32 like a bigger version of the Pro4 Grip, Specialized Turbo or Vredestein Fortezza Senso.