In addition, the facades of structures located in the business district shall be one solid, neutral color and the color should be limited to: cream, light to medium beige (tan), light to medium grey. Any facade existing on the effective date of adoption of this section, which does not conform to any provision hereof and which has previously been approved by the Building Department, shall be deemed a nonconforming use and may be continued. Any legal nonconforming facade of any premises involving a change in tenancy of said premises, requiring any painting, or involving a change of appearance, signage, awning, shall revoke the nonconforming rights. Permits are required from the Building Department before any painting may be done to the facades of any structures located in the Business District.