Dwi laws extend into your locked garage.
As the law is worded “ anywhere in the state “
When your warning light flashes white to the rear
Subd. 4a.White light.
(a) It is unlawful to project a white light at the rear of a vehicle while traveling on any street or highway,
Red is out,
169.073 PROHIBITED LIGHT OR SIGNAL.
(a) No person or corporation shall place, maintain or display any red light or red sign, signal, or lighting device or maintain it in view of any highway.
Subd. 2.Colored light.
(a) Unless otherwise authorized by the commissioner of public safety, no vehicle shall be equipped, nor shall any person drive or move any vehicle or equipment upon any highway with any lamp or device displaying a red light or any colored light other than those required or permitted in this chapter.
Subd. 6.Flashing amber light.
(a) Any service vehicle may be equipped with a flashing amber lamp of a type approved by the commissioner of public safety.
The catch is how your state defines things.
“public highway." Under some stay Laws, any property that is open to and readily accessible the public fits this definition. The police can issue tickets.
Like,
Subd. 81.Street or highway.
"Street or highway" means the entire width between boundary lines of any way or place when any part thereof is open to the use of the public, as a matter of right, for the purposes of vehicular traffic.
“Open to the use by the public “
Like the lanes that are marked in a parking lot.
While you may be able to run whatever color
(Like green)..you choose at som point your going to be on the public roads and your light will then be illegal.
Why not run all amber?
How has the weather been in your neck of the woods? 
