The answer to 'why is my dryer vent discolored' is that it is likely caused by lint buildup or excessive heat. Over time, lint and debris from your clothes can accumulate in the dryer vent, causing it to become discolored and even catch fire if left uncleaned. This discoloration is a sign that the vent needs to be cleaned to ensure proper airflow and prevent potential fire hazards.
Discoloration can also be caused by excessive heat, which can occur if the vent is blocked or if the dryer is not venting properly. This can lead to overheating and damage to the vent, causing it to become discolored and potentially even melt.