She's an absolutely beautiful looking plant, optimus -- congratulations!
While some of her pistils have changed colour, most of them still look quite firm and white and juicy. As she gets closer to ripeness, the pistils will darken, wither and shrink inside the calyxes.
As MassMedMan's photo shows, the overall colours of the plant and its foliage will continue to fade and change and look more autumnal Fan leaves will turn yellow. You'll know you're getting close then.
Are you using any chemical nutes? If not, you may not need to flush at all in soil -- it's a hotly debated topic
Yes, I'm running/testing a new nute line (free samples) for that plant only and I did flush on Monday. I don't use a lot of nutes and almost never flush, but occasionally I do. The fade to yellow has been natural,, and last week I'm seeing some purple. Rock hard buds. I almost have no white hairs,, honestly,, I don't check trics until 90 pistols are red/brown.
Be patient,, this plant was very popular with friends this summer when I ran it...