Colorado Revised Statutes Title 24. Government State § 24-82-902. Outdoor lighting fixtures funded by the state--standards

(a) For outdoor lighting fixtures with a rated output greater than three thousand two hundred lumens, the fixture is a full cutoff luminaire;

(b) The minimum illuminance adequate for the intended purpose is used with consideration given to recognized standards, including, but not limited to, recommended practices adopted by the illuminating engineering society of North America (IESNA);

(c) Full consideration has been given to costs, energy conservation, glare reduction, the minimization of light pollution, and the preservation of the natural night environment; and

(d) For purposes of lighting a designated highway in the state highway system, the department of transportation determines that the purpose of the outdoor lighting fixture cannot be achieved by the installation of reflective road markers, lines, warning or informational signs, or other effective methods that do not require the use of artificial light.

(a) A federal law or regulation preempts state law;

(b) The outdoor lighting fixture is used on a temporary basis to provide illumination for emergency personnel in an emergency situation;

(c) The outdoor lighting fixture is used on a temporary basis for nighttime work;

(d) Additional illumination is required for a special event or situation; except that any additional illumination required for a special event or situation shall be installed so as to shield the outdoor lighting fixtures from direct view and to minimize upward lighting and light pollution;

(e) The outdoor lighting fixture is used solely to enhance the aesthetic beauty of an object; or

(f) A compelling safety interest exists that cannot be addressed by another method.