My experience has been just to let them go till done
.....Do you know what strain you have? You could look up info on how long it takes...however, anything can make a plant take longer to be "done", from heat stress, to over watering, to nute factors, etc....so, if it were mine, I'd just let it go a little longer at least...my 2 cents.
I did have this strain once, "the great white shark" that was a POS and the trics never ever turned even after over 16 weeks...talk about a disappointment..But your looking good from what i can see