Under sail at sea, a masthead tricolor would be good. Under sail, for coastal and harbor work, a bicolor bow light with a stern light would work.
Under power, you would need a white stern light and a white steaming light and the bow bicolor light. At sea, the masthead anchor light would work for the white stern and steaming light, which can be combined as a single all-around white light. Inshore, I would recommend using separate stern and steaming lights.
A strobe and a powerful spotlight are both good for safety, but be careful with the spotlight, as if you blind people on another boat, you may be liable for any damage that occurs from their inability to see.