They really are looking good.
You asked about them fattening up. I also notice how much attention you are paying to the color changes in the pistils. Let me help you understand what you are looking for in a different way.
Your pistils emerge from the calyx. The calyx is where all the good stuff will be happening. As you enter into late flowering, those calyx will begin to swell with oils, preparing to make seeds.
As they swell, your pistils will appear to get smaller. This is an effect caused by the plant searching for pollen to make those seeds. Without that pollen, they just swell with even more beneficial oils.
I say all this to help you understand why I don’t worry about trichome coloration until after I notice that swelling.
Trichomes build, degrade and get replaced throughout the plants adult life. Even before the calyx begin to swell, you will see amber trichs. Don’t let her fool you.
Once the swelling of late flower begins, a whole fresh new batch of clear trichomes will show up! This will be your final coverage that you will want to keep an eye on.
Just be patient and watch to see that what I’m telling you is true. I’m hoping that it will also help ease your concerns about missing that “sweet spot” for harvest.
Plus, only you will be able to determine what “sweet spot” is best for you for individual strains. Each one has different effects at different maturity levels.
Enjoy what you have coming…