– You'll need substratum app from Play Store to apply this theme.
– You can use it as an add-on with any substratum theme or as a standalone theme.
– Icons will follow accent color from your ROM/theme.
– I covered system icons for Oreo/Pie Google stock and a lots of AOSP based custom ROMs. OOS is not supported. If you find any unthemed icon in your favorite ROM please contact me via email and I'll try to add it in the next update (screenshot and name of the ROM are required)