How to add more themes in Blekota note 4 rom

Hi,im new in XDA,but i already have a question about how to add more themes in Blekota note 4 rom.
I've been searching everywhere to find a solution but i couldn't find any so i hope someone knows something about that. :)
I can see a button for galaxy apps but there are no themes in there.
I really hope there is someone who can help me.