I think the link Blackzilla posted pretty much answers the question.
I ran into this when I wanted to pint my tail lights. I had them done professionally with a 'light' tint, and then proceeded to actually check if they were visible under the conditions required in our province, and that the 'color' of the light was not subject to interpretation. When I was questioned by the police who were willing to ticket me on the spot, I offered all the information i had collected, and offered to provide them with a real life demo on the spot, or we could go the court route where I was willing to (on principal alone) fight this so hard that they would never even consider writing up someone again, even if they didn't pass the requirements.
I made my position clear - I did the research, have the documents, ran the tests and am willing to run the real life tests for them at any time. However, if you drag through the court system, I will treat it with the same level of respect I was shown while being completely cooperative.
I did NOT get a ticket, and have not provided a demo as they felt I had my ducks lined up pretty good, were impressed with the documentation and thought I had a pretty darn good looking truck! I felt the officers both had good taste. :smileup: