If you can see amber tints WITH YOUR NAKED EYE I say it is time to harvest, although only a loop will tell you for sure. Once everything turns amber the game is over and your harvest is ruined, only to be sold as schwag.

I've had the (dis)pleasure of smoking indoor bud with full amber trichs. An unfortunate experience I never intend to repeat. If it's brown (i.e RED) turn it down.