The answer to 'why is my pressure washer discolored' is that discoloration on a pressure washer can be caused by a few common issues. The most likely causes are mineral buildup, rust, or corrosion from improper storage or use of harsh chemicals. This discoloration is usually just cosmetic and doesn't affect the performance of the pressure washer, but it can be an indication of more serious problems if left unchecked.
If the discoloration is just surface-level, you may be able to clean it off yourself using a mild detergent and a scrub brush. However, if the discoloration is accompanied by other issues like decreased pressure, leaks, or malfunctioning parts, it's best to have a professional technician take a look to diagnose and resolve the underlying problem.