Because the hiragana ends with an う sound, you know this word is a verb. The kanji itself means dirty so the verb vocab version is to get dirty. You know you're not doing the dirtying, because it's rare (れる) for you to get anything dirty, though things do get dirty on their own.
Things seem to get dirty easily around here, which is why you go (よご) to great lengths to keep things clean.
I don’t recommend white controllers because they get dirty easily.