I'll have to check to be certain, but I'm pretty sure they're DeepSeaCrabBiolucentPurple and DeepSeaCrabBiolucentBlue, respectively, which are actually the two skins that are normally used underneath the other skins to give the purple or blue markings on the crabs. But they look pretty cool exposed like this!
This will be Noah's work, of that I am certain

Also very cool to see a bright purple pet. There aren't many quite like this.