Thats a tough one to answer haha, I'm not sure if anyone here could give you a reasonably accurate answer on that question. It varies so much from strain to strain and different growing conditions. All you can really do is watch it closely. I've had plants that can change heavily in a week, and another one I am thinking of specifically that was probably 3-4 weeks from the time I saw the first amber trichs to the time I harvested at less than 50% amber trichs. Then after drying and curing it had more amber trichs than white/clear. Indica vs sativa probably has the most to do with the trichome color conversion time. Being that you're growing an indica it should mature faster. Maybe someone else here can give you a better idea than I can but its just a game of patience. Post some pics if you can.