How to use Substratum and Andromeda to install custom themes on Android Oreo devices without root

Last month it was discovered that with the release of Android 8.0 Oreo, users would be able to theme the operating system’s UI without the need to root their handsets. With the use of the Substratum theming engine, users can use Android’s Overlay Manager Service (OMS) to change up the look of almost every aspect of the OS. Here’s a quick look at how to do this…

Before we get started, there are a couple of things to know. Substratum on its own requires the use of root to modify and theme Android. Thankfully, the developers behind the engine have published a new app called Andromeda (and no, it isn’t the Andromeda that you’re probably thinking of). Using this application as well as a desktop client will elevate Substratum’s permissions and allow it to fully modify the OS’s appearance.

Another thing to remember is that every time you reboot your phone, those permissions will need to be elevated once again if you wish to continue theming your handset. Thankfully, a simple reboot won’t wipe any themes that you have enabled previously.

How to install custom themes without root

Getting started: The prep work

1. Download the Substratum application from the Google Play Store for free
2. Download the Andromeda application from the Google Play Store for $2.49
3. Download the Andromeda desktop client for MacOS, Windows, or Linux from XDA
4. Enable Developer options and USB debugging
   1. Open your device’s Settings menu
   2. Scroll down and tap on System and then About phone
   3. Locate Build number at the bottom of the list and quickly tap on it seven times in a row
   4. Tap on the back button and enter into Developer options
   5. Toggle on Developer options at the top of the menu
   6. Scroll down and toggle on USB debugging
5. Plug your Android Oreo device into your computer
6. Run the Andromeda desktop client and follow the on-screen instructions
7. Andromeda will elevate Substratum’s permissions and the application will automatically open

How to install custom themes

Once you have Substratum up and running, you probably want to go ahead and install a theme (that’s the entire point of this guide, right?). It’s pretty simple: you can find Substratum-compatible themes on the Play Store. Some are free, some are not. But there are plenty of options.

1. Download Substratum compatible themes from the Google Play Store. Some themes are free while others cost various amounts
2. Once installed, the different themes will appear in the Substratum application
3. Select whichever theme you would like to implement or modify
4. You will be presented with a list of different sections that can be modified such as the Android System, System UI, Settings menu, Navigation buttons, and more
5. After you have set your preferences, check the box next to each item you would like to theme and tap on the floating action button
6. Select Build & Enable
7. The process to compile and theme your smartphone can take several seconds to close to a minute, depending on the amount of theming is taking place
8. Your device should now be themed to your liking

Note: During our testing, not all of the theming worked after it was compiled and enabled. Doing a quick restart and reauthorizing Andromeda appeared to fix any items that didn’t theme properly.

How to remove custom themes

If you have a theme installed and would prefer to go back to stock (or you want to switch themes), that’s pretty easy as well. Just follow the below instructions.

1. The easiest way to remove all of the themes currently enabled on your device is to go back to Substratum’s main window
2. Swipe in from the left side to display the app’s main menu
3. Select Recovery
4. Tap on Restore Theme
5. Any themes enabled on your device will now be disabled and your phone will appear as it did out of the box
6. Additionally, you can go into any of the theme’s settings that you have enabled and manually disable them individually (although we found this didn’t always work)

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