Pumpkin is one of the older, hard-to-find Mosser collie colors. It’s a medium-light opaque yellow mixed with subtle orange. Also available as pumpkin satin (on the right below) and pumpkin carnival.
In 2017, some similar looking collies were produced by Rosso Glass using the Mosser moulds. If you look closely, these have a more “neon” orange and the yellow is almost mustard colored. This is very different from the subtle colors of the original pieces. They are usually referred to as “orange marble”