Swift Dark Substratum theme makes more than 200 apps dark. What's special about it is that it supports a big number of systems and that it themes such a big number of apps. It also, in a balanced way, preserves most apps original accent and primary colors.
INSTALLATION INSTRUCTIONS: 1. Download & install the theme. 2. Open Substratum App or from Dashboard click on the fab select apply theme 3. When Substratum is opened give it full root permissions and also allow system modifications.
A bare-bones Black theme for Android Oreo that focuses on nothing more than theming the system. The theme is best used with STOCK or AOSP based ROMs. It will definitely work on any Android Oreo system, but it will not theme it as perfectly as on vanilla Oreo.