Cal. Pub. Util. Code § 5411.3

Every charter-party carrier of passengers, and every officer, director, agent, or employee of a charter-party carrier of passengers, who displays on any vehicle any identifying symbol other than one prescribed by the commission pursuant to Section 5385, or who fails to remove an identifying symbol when required by the commission, is guilty of a misdemeanor and is punishable by a fine of not more than two thousand five hundred dollars ($2,500), by imprisonment in the county jail for not more than one year, or by both.