you should harvest. But you should check the trics on the leaves just to make sure. When THEY are opaque at their tips is usually the same time that about 70% of those hairs will have turned brown. That's why there are different ways to tell, the BEST way is w/ a microscope and to check the leaves for the little mushroom-looking things when they turn opaque is when you harvest. I don't use a microscope, I have good eyes, and w/ my last grow, I could literally see them with just my eyes. But, I guess not everyone can see that well, ( i also paint miniature figurines so am used to up-close work)
so to each his/her own
not having a microscope, a magnifying glass will also work in a pinch