The answer to 'patio yellowing' is that it is a common issue caused by a variety of factors, including environmental conditions, improper maintenance, or underlying problems with the patio material. Symptoms can include a dull, faded appearance, discoloration, or a yellowish tinge to the surface.
Some common causes of patio yellowing include exposure to sunlight and UV rays, water damage, mold or mildew growth, and chemical stains from spills or cleaning products. In some cases, the yellowing may be a result of the natural aging and weathering of the patio material itself.