I'm 47 but when I was a teenager you could buy "sachets" of hair dyes which were a kind of wash in wash out colour. They didn't last but they were only a quid or so.
I've been looking for something similar - I don't want a semi-permanent box dye but just something to enrich my colour and give me a bit of shine for a night out.
Is there an alternative to these nowadays? I can't find anything which is similar. Any ideas?