When you open the theme in the substrate application, you will see the drop-down menu above the overlays. You must choose a function from your Android ROM version. There are also overlays with different variants for the specific Android version.
Some applications like PSBA Clock, Mail, and Gallery may or may not work, because each custom ROM has its own variant of these applications, so if you get an error while compiling, just do not install them.
+ Theme works with Google’s stock-7.1.x / ROM 8.x (Note that ROM actions have thematization limitation)
+ Theme does not work on devices that do not meet the above requirements
+ You need the Play Store Substrate app to apply the theme
+ You must be rooted
Supported Android
{7.0 and UP}
Supported Android Version:-
Nougat (7.0 – 7.1.1) – Oreo (8.0-8.1)
Download Mono Art substratum 17.7 Patched APK For Android