These still have some time to go, another 2-4 weeks maybe.
Start a flush when there are 90-95% brown pistils and harvest at around 95-98% brown pistils, this will give you buds with peak cannabinoids and your trichomes will be in the 10-30% amber zone.
Otherwise there is no reason to flush "just because", this just ruins the microbial life in the substrate.
Hope this helps, Organoman.