You must use a Marshmallow or Nougat ROM that fully supports Layers / Backgrounding theming!
This theme requires you to be rooted and have the subjectum substratum application installed.
Warning !! I do not support, and will actively ensure people who illegally download paid apps, receive no customer service from me.
The basic theme is dark blue, but individual applications are usually the theme with their respective colors (ie. Hangouts is green, Messenger is blue).
20+ thematic applications (plus updates)
5 accent colors (will add more support for the variation of color in future updates, as well as new colors)
System wide thematization including settings, google now, volume panels and pop-up, and quicksettings
For More Info Google Play
varies with device