I had never seen a worm quite this color before. The body can be bright green, blue-green or brown, and the parapodia lobes light in color. They can be up to 100mm in length, so this was a very "small one". It lives in mucus tubes amongst algal frond or holdfast, or in mussel beds. (Thanks to Marlin Harms for the species ID, as I only knew the genus). Marlin found this beauty. Great day we had, Marlin.