Does this walmart have a paint center, where you can get custom color indoor paint by the gallon?

Yes they do, its in the north east corner of the store

It does but it takes 30 mins or more to get any kind of help there.

They do

Yes. I am sure if you go in and ask where it is located an employee will help you. That or go to the back right or left corner and that's where most of them are found