I took a break and am back in full swing but I forgot if it is a potion I need in order to change the species of my pet? Also how do I change their color?

Miracle Potion II is the potion that you need in order to change the species of your pet but keep the color. It's a CS item though, and it's 1000 CSC. If you don't care about keeping your pet's color, there are elixirs available for most of the species.

For the most part you need a potion in order to change the color of your pet. There are some that require doing certain things and/or specific items other than potions, like Hydrus, Galactic, Steamwork and Nostalgic. Alternatively, you can also zap your pet, but it is, of course, random and there are multitude of other outcomes other than changing your pet's color/species. The zapper cannot change your pet's species without changing its color though. Only the Miracle Potion II can do that.

An Elixir will also change the species of your pet, but it'll also change it to the color mentioned in the name, eg.