USE AT YOUR OWN DISCRETION ON A SAMSUNG DEVICE !!! * Does not work properly so far as I am aware.
Must be rooted and have the application substrateum Theme of the engine!
+ Make sure you choose the options you want for the PSBA, Android, Settings, and SystemUI keyboard.
+ Press the fab button (large round button with brush icon)
+ Press Compile and Activate
+ Restart SystemUI from application substrate if necessary
+ SystemUI
+ Telecom
+ TeleService
+ Textra
+ Twitter
+ WhatsApp
+ YouTube (* Flash Theme Ready ZIP)
For More Info Google Play
Supported Android
varies with device
Download Substratum Spectrum Theme 12.2.1 Patched APK For Android