Every vehicle covered by a certificate shall have a color scheme, insignia and cruising light of a design approved by the Director. Each such color scheme shall be clearly distinguishable from that used by other associations or owners. The Director shall designate a color scheme exclusively for vehicles that have met the standards required as of January 1, 2020. Changes in color scheme, insignia, cruise light design, or the addition of advertising or advertising devices or bumper stickers, shall have prior approval of the Director. The name of the taxicab company, owner or association shall be clearly painted on both sides of all taxicabs in letters at least three (3) inches in height. A medallion issued by the Director and the number of the certificate preceded by the "PG" designation shall be displayed on the driver side front panel and rear trunk of the vehicle. The certificate number shall be displayed in figures at least three (3) inches in height, and contrasting in color from the background colors as follows: PG 900. The Director shall issue a medallion in a color scheme to differentiate between an individual owner certificate and multiple owner certificate required under Sec. 20-152 of this Subtitle.