Such a 1940s colour...soft minty green
These buttons are a substantial 2.7cm wide, made of casein plastic.
These were made in French Canada in the 1940s in the shape of propellers so the population could show their support for the war effort by sewing them onto the clothes they made.
They are 2.7cm wide and I have them in cards of 6 or 12.
The cards of 6 have a little picture of wings, with a button in the middle, at the top!