pistles just turnes light brown (amber)?

the pistles just turned light brown..am i able to determine how much longer from that and if so how long??. im trying to judge when to flush nutes before harvest. someone please help! thanks

Pistils will turn brown throughout the entire life cycle after starting flowering, the color judgment process on when to harvest is based on the crystals, not the pistils.

Hope that helps

I'd start flushing now or soon, generally speaking when 50-80% of the pistles have turned brown/orange it's time to harvest (depending on what high you want)
As mentioned though, you should go by the state of the trichs to determine you perfect time to harvest.
Invest in a 30x jewellers loupe or something similar.