This is Mosser’s popular cobalt blue collie in an uncommon satin finish. Not everyone is a fan of the satins, but I like them a lot. Displayed with backlighting, these darker satin collies emit a beautiful, subtle glow.
Mosser sold collies in clear cobalt glass and cobalt carnival for a number of years – they are fairly easy to find and frequently show up on eBay or Etsy. The cobalt satin – not so much.