Copyrigth on frameworks for theme development wordpress.

I ve been all day browsing this forum and i didnt find a answer to my question.

I’m thinking about developing a theme using Reddux but i want to know if have to change the functions prefixes or how to credit to the authors (or even if i have to give them the credit ), will envato reject my theme if i use a framework? what i need to know to start using a framework for theme development on envato? (talking about legal an license stuff).

Please someone help me .