1.  The color scheme and insigne of the taxicabs of each certificate holder must be readily distinguishable from the color schemes and insignia of other certificate holders operating in the same county.

2.  The Taxicab Authority shall allow a certificate holder in any county to place advertisements on the exterior of the vehicles used as taxicabs in the operations of the certificate holder, provided that the placement of the advertisements does not impair the ability of the driver to operate the taxicab safely.