Just to clarify -- the "hairs" are pistils, and they will often turn red or darken as the plant matures in flowering. The color they darken to and the percentage of pistils that turn dark compared with the ones that stay light is dependent on the strain. But in general, most of them will turn dark and recede back toward the bud when it's time to harvest.
Trichomes are the tiny sacs of resin that give the plant its snowy appearance. Trichomes are also where the THC is concentrated. Trichomes start clear, turn cloudy/milky as THC peaks and then turn amber as the THC degrades. So amber trichomes means your plant is passing its peak in terms of THC potency and you should cut.
It's hard to see if the trichomes are amber without a 60x magnifier but you should get one to see clearly when it's time to harvest. 5% clear, 90% cloudy, 5% amber is a good proportion to shoot for.