The answer to 'window cleaning discolored' is that discoloration on windows can be caused by a variety of factors, including mineral deposits, hard water stains, and environmental pollution. This can result in a hazy, streaky, or cloudy appearance on the glass.
Some common causes of discolored windows include: hard water residue, which leaves behind mineral deposits; oxidation of the glass surface over time; and environmental pollutants like dirt, grime, and smoke. Proper cleaning and maintenance is important to prevent and remove discoloration.