Iowa Code § 321.422: Red light in front — rear lights.

1. No person shall drive or move any vehicle or equipment upon any highway with any lamp or device thereon displaying or reflecting a red light visible from directly in front thereof. No person shall display any color of light other than red on the rear of any vehicle, except that stop lights and directional signals may be red, yellow, or amber.

2. This section shall not apply to authorized emergency vehicles, or school buses and vehicles as provided in section 321.423, subsection 6.