Fresh water tanks....Can they be Black in Color?

yep, boondocking has an bottomless tank for grey water. We do our best to use biodegradable soaps. If we're out for an extended stay I dig a small hole under the drain, then crack the grey water valve and let it dribble out. contains the water and if something does make it through you can pull it out of the hole before filling it in. Dirt/gravel make great filters.