Black and gray cotton denim fades by design: the dye sits largely on the surface of the yarn and wears away with friction and washing. Washing rarely, inside out, in cold water, and air-drying slows that process; accepting some fade is part of owning denim.
Leather wants occasional conditioning and protection from soaking and heat. Wool tailoring prefers brushing and airing to frequent dry cleaning. Technical shells should be washed with membrane-safe detergent and have their durable water-repellent finish renewed when water stops beading. White fabrics of any kind benefit from immediate spot-cleaning.