like drenots said, trich color is not enough of an indication when it comes to when to harvest your plants.
also, to my understanding, and after much reading - THC breaks down only when trich heads start to look like they're deformed (which makes the most logic).
i harvested a bagseed little early, buds came out too much fluffly, they make you high, and i do mean high, due to the early harvest (comparing to the bud they came from, which was a total "one hit wonder") but almost no taste, and smell, they could definitely use an extra week or 2 before harvest.