Your light is too yellow/amber to actually make a judgment on that based on the trichomes, it makes every head look amber tinted already.
You also want to make sure you are looking at the calyxes (closer to the middle of the bud) and not the small, dark green sugar leaves sticking out because those mature/turn amber faster.
Judging by hairs only I would guess 2-3 weeks is a good estimate, but you gotta look at trichs
Nice strong plant.