.CMMTHEME File Extension
File TypeCleanMyMac Theme File
What is a CMMTHEME file?
User interface theme used by CleanMyMac, a program that improves Mac OS X performance by removing unwanted files; saves a visual theme that alters the appearance of the buttons, graphics, and other visual elements.
Themes are stored in the ~/Library/Application Support/CleanMyMac/Themes/ directory. Downloaded themes can be manually placed into this directory.