Cleaning your earphones on a regular basis will ensure the best possible sound performance and prevent them from wearing out sooner than expected.
Use only a slightly damp cloth when cleaning the earbuds and/or case. You can also use a fine brush or cotton swab to gently clean inside the case, avoiding damage to the charging connectors (copper pins). While the N3 Pro earbuds and case are sweat- and splash-proof, subjecting them to high moisture levels could lead to permanent water damage.
Keep in mind that with time, some discoloration may eventually appear. This is most common if the earbuds or charging case continue to come in contact with dirty surfaces or materials over extended periods of time.