I daresay,reversable outerwear has been around for decades, but these were must-have items in 1960's and early 1970's.
They were made of nylon (quilted,I think), mine was blue,until it was turned inside out, when it was red.
I had one in my school and used to imagine I was "undercover" in disguise if I had my anorak round the blue way - as if any CIA agent would be that focused on my particular anorak to say "Hey, where's that kid gone in the blue anorak, there's just one kid in a red one"
Do You Remember Reversable Anorak?
Do You Remember Reversable Anorak?