When they turn color it means that they've either been pollinated or have simply lived out their lives. If it were my grow I'd be letting them go until they're damn near 100% cloudy, I don't really care about amber because they turn after harvest, too, and I am not a big fan of couchlock.
Bigger, more important question for me is this--are they popping NEW pistils? If they're popping new pistils and those buds seem to be growing, don't short-change yourself, let them go as long as they need to if at all possible.