Why is it Purple


https://www.sylestia.com/view/pets/?petid=7284888

Those pets are from the Summer Festival. They were created by collecting 9 different Mermaid Shells, obtained by the Beach Seeking game, that were then combined to create a pet with one guaranteed restricted wild trait and a certified name. All those pets were Summer Fest themes as well.
These certified names are in purple to represent that they have a certified name generated by the site rather than having been named by a user.
Here's the summer overview for a little more information:
https://www.sylestia.com/forums/?thread=103410&page=1

It's basically a way to make the pet a little more special. Outside of the Summer Fest theme pets created from the Mermaid Shells, there were a couple of other themes from other events, such as past Easter Events, and some of the site games(these pets aren't themed, but have a certified name), that came with certified names as well.

Here's some other examples of pets with certified names(All pet photos are clickable and lead to the pet's profile page):



But basically, if the pet's name is in purple, it just means it has a site-generated certified name. I hope this explanation helps. ^^