According to the following press release from Stellantis (dated September 1, 2022) - Hydro Blue is listed as an available exterior colour for the 2023 Ram Heavy Duty.

https://media.stellantisnorthamerica.com/newsrelease.do?id=24053&mid=

I checked the ramtrucks.com website. Hydro Blue is not listed as an available colour for the Ram 3500.

https://www.ramtrucks.com/ram-3500.html