I hail from Holly, a town very close to yours Pyrandon. If you have a gaming group with an opening maybe I could join you. I would occasionally offer to have the group play test material as it is developed.

As to the river and or well. There is a fresh water source at the Keep located up top. All water is controlled from this point. The natural decline from the keep to the light house allows gravity to send water into cisterns. The plumbing is not visible and most houses have small cisterns that could pump the water in. The colors are choices made by the locals for their dyed thatching or tiles, depending on the structure.