You got that right! I remember accidentally shattering an S-10 Blazer driver's window once; I could not find a proper factory tint window to save my miserable soul...and wallet. Cost me nearly $300, and that was from my brother's boss.
Same law in California I know for sure. Front door windows and windshield must not be tinted any darker than the way it came from the factory. further toward the rear, you can paint the glass black if you want to. Not sure what the Oregon law is......... I've never seen a need to pay for my own window tinting. Had a few vehicles with factory 'privacy glass'.......