Moon-Glow Vintage Bangles

I found these vintage moon-glow plastic bangles separately. The first one I found was the mint green one; this one reminded me of a bangle I owned when I was very young. After that I discovered the salmon coloured one, and just a few weeks ago I picked up the blue bangle. I think they will look gorgeous in the summer when worn together with a summer dress or just a t-shirt!

I don't know much about these but I believe the bangles, if original, could go back to the 60's or 70's. Your opinion would be welcome.

Thanks for looking:)