Good to know yellow is a standout,
since that's the color of my deck. While our water up here is very clean, gunk still happens. This past summer saw major honeydew secretions which in turn created sooty mold on everything from decks to siding to outdoor furniture.
Dish soap, warm water, and a Mr. Clean Magic Eraser easily cleaned up my Carbonlite 2000 boats. The RM boat took a bit more elbow grease plus an application of 303 to make it look presentable.
The eraser also cleans up the white hull, so the scratches are barely noticeable.
Would a brightly colored keel strip make a white hull more easily spotted from the air?