Tennessee Code Title 8. Public Officers and Employees § 8-8-219

(a) White patrol cars which have a green stripe running horizontally along the upper portion of each side may be used exclusively for county sheriffs' patrol cars, and this color scheme shall not be used by any other law enforcement official or agency. When adopted for use by a county sheriff's department, the stripe design as well as other emblems and lettering shall conform to the official uniform markings adopted by the Tennessee Sheriffs' Association and on file with the executive director of the Tennessee Sheriffs' Association. These uniform markings may be used exclusively for county sheriffs' patrol cars and shall not be used by any other law enforcement official or agency.

(b) Nothing in this section shall prohibit a county sheriff's department from operating unmarked cars for undercover or other purposes.