I see a few amber looking ones in there, looking pretty good. My last grow I let go 11 weeks waiting for the amber change but it never really happened. Finally after no nutes for like a month I figured enough and chopped them, they smoke great. I'd go for overall ripeness, like autumn colors, retracted pistils, swelling etc. Looking at trichs alone hasn't been working for me.
What did you use for the pics, however. They are super close up!