Dale, as for what shade is acceptable I would recommend you stopping at a place that puts on tint film. They have a scale or pieces of glass, or film, to show you what is legal and what is not.
I just bought new "smoke" glass for my panel here locally. Since the rear doors is curved I took them to a film tinting place and picked out the tint I liked best....which happened to be just a bit darker than my side glasses....but they on the rear and will not be noticed much, if at all.
To get something like orange I would think you will have to have the glasses film tinted ....just my guess, unless special order from a glass company.
