I was discussing alternative hair dyes with someone, who pointed out that in Grease one of the Pink Ladies (can't remember her name) has pink hair. Is this an anachronism? Were these hair dyes even available in the 50s/early 60s and if they were, was anybody 'brave' enough at that point to use them?
Hair dyes date back to ancient times. A more recent example of recipes can be found in the Toilet of Flora from 1779. To darken, anything from a regiment including oil of tartar to burnt cork is recommended. Lightening can include many things, often based around lye as the bleaching agent. While it doesn't mention any unusual hair tones, they do have recipes for colored hair powders that can create a strong effect. Rose (modern pink), blue, and other tones can be found in examples as well. This portrait is one of my favorite examples of 1780s hair.
There are some examples as of the 1930s for un-natural hair dyes. By the time we reach the 1950s there is definitely a trend for pastel colored hair. It's by no means a huge thing, but there are surviving advertisements for at least lavender and pink.
In the movie Grease, it's noted that Frenchie's pink hair is a result of a mistake in her dying techniques and wasn't on purpose.
