Becoming blonde

I've always sort of liked my grey/white hair - but now, for some reason, it's turning blonde. Not the pretty kind, either. So far remedies suggested are:
* mix baking soda with your shampoo
* purple shampoo (when I tried this years ago, whole head was purple)
* stop smoking (done about 40 years ago - probably not a factor now)
* stay out of the sun

Nothing has really worked. Maybe the usual Head and Shoulders I've been using for years (and just bought a big bottle from Sam's) has a new formulation, or maybe I need to use more conditioner.

But now I've researched all the local CVSs and Walgreens and Targets - no purple shampoo of any kind! What does that say about their demographics? Are there no women with white hair they need to service?

I did find Sally Beauty Supply (close to Stein Mart) and got some new purple shampoo, but resisted the gel (yuck to have it on your hands) and the spray.

I'm going back today to get both.