I used Jack Keller's and modified it. I tossed in a bananna for a bit of body and used some OJ for a yeast starter.
When I tried it, it was really harsh and acidic. I knew better from reading these forums, but I panicked and sweetened it. It was supposed to be a dry, but I don't think it would have worked. It's still sitting in the jug to be bottled. I'll see how it turns out.
Blue rinses were very fashionable with the grey haired crowd in the 70s mainly, there are still a few around but most not that extreme, they usually go for sutle shades of mauve and light pink grey.
I know this because I used to be a hairstylist and even had a couple of the rinse brigade as clients.
Nearly right on the way its done Luc, normally the ladies hair is naturally white already but some bleached it to get it light enough which was using the peroxide but the actual rinse stuff itself has none of that in it, its literally just a rinse of colour and washes out at the next wash. Hideous messy stuff