Flush ?

Those appear to be the trichomes on the sugar leaves in your shots. You need to be looking at the trichomes on the calyx. Judging from your bud pictures, you've still got a bit to go. Pistils still look fluffy. Once about 70% of the pistils start drying up is when I'll start checking trichomes. Once you trichomes are say 70% milky 20% clear 10% amber is when you should cut, things will continue to convert during the cure process. I'd start the flush once the pistils are where they need to be and that should time out. However, don't know if you are doing soil or hydro or a photo/auto. These would all affect timing of things and type of flush.