Harvest rule of thumb

So I’m getting close. My main cola has about 70/80% orange hairs but the rest of the plant is still white. Do people harvest as different plant matures or harvest the whole plant once say 50/60% is orange

It’s the trichomes you want to watch and in my limited growing experience I have cut main buds first and lowers about a week layer

The "hairs" aren't what get you high. Look at the trichomes under a loupe or use your phone to take a closeup and zoom in on that image. Look at the trichomes, the little balls on the top of the trichomes will change from clear to cloudy to milky to amber. Amber means they are degrading. I like to chop when trichomes are mostly milky with a few amber starting to pop up. That means you have reached peak potency and it's starting to go downhill. Some people let it go longer because they like the high from the amber trichomes, more couch lock.