After a lot of teasing, Team Substratum and XDA-Developers are proud to announce the release of the Andromeda add-on for Substratum which brings full custom theme support for any Android 8.0 Oreo device without root. We realize that many people are excited by this project, but there are many people who feel that this news has been overwhelming for them in the amount of technical details we've been relaying. For those people, we want to reassure you that the end product is simple enough to use for your average user, and that it does not require you to understand how to use complex scripts or ADB commands. This tutorial is aimed at showing you how to set up and install the new rootless Substratum, and then use the theme engine to install custom themes.


How to Install Custom Themes on Android Oreo using Substratum

Requirements:

  • Android 8.0 Oreo device
  • Access to a Windows, Mac, or Linux PC

Prerequisites

You will need to download and install two applications on your phone. First, download the install the Substratum theme manager app. This application is free and is needed to manage your themes.

Next, download the Andromeda add-on. This application is a paid application.

Finally, download the Andromeda desktop client (available on Windows, Mac, and Linux) for your particular operating system from this XDA forum thread. Extract the .zip file if you are on Windows/Linux, and save the contents of the archive to any folder on your PC. For the Mac .dmg file, leave it as is.

Part 1 - How to Install Andromeda

  1. Enable Developer Options and then USB Debugging
    1. Open up the Settings application on your phone.
    2. Scroll down and tap on "System."
    3. Tap on "About phone."
    4. Scroll down and tap on "Build number" 7 times until you see a toast message that says "You are now a developer!"
    5. Go back to the "System" settings and you'll now see a new "Developer options" menu.
    6. Enter Developer Options. Note: it may ask you for your device's pin/password.
    7. Find and enable "USB debugging."
  2. Open up the Andromeda application on your phone. It should say "Disconnected" for the "Connection status."
    How to install custom themes on Android Oreo
  3. Connect your phone to your PC using a supported USB cable.
  4. Run the Andromeda client on your PC that you downloaded earlier.
    1. Windows: Over on your PC, open up the start_andromeda.bat file. It may ask you for "administrator" rights. If so then grant it, and you will see a command prompt open up. After pressing enter, you'll see a bunch of ADB commands be sent. These commands are setting up the Andromeda add-on so it can run independently of your PC.
    2. Mac: Click on AndromedaClient.app. It will ask you to select the "disk image of the mounted Andromeda client." Press continue, then when your file browser pops up, look for "Andromeda" under the "Devices" list. Select it and click continue. Here is a quick video showing these steps:
    3. Linux: Click on the start_andromeda.sh script file. You should see a terminal window open up and a few commands running, much like the Windows version as shown above.
  5. Once you have run the Andromeda desktop client above, you will immediately see the Substratum application open up on your phone. If it did, then the script worked successfully, and Substratum can now manage themes without root and without needing to be tethered to your PC! To verify that the script worked, open up the Andromeda app again, and the connection status should now show a green "Connected."
    How to install custom themes on Android Oreo

Now the Andromeda service is up and running on your phone! This service is killed whenever you reboot your phone, so if you want to change any themes in the future, you will have to simply plug in your phone and run the desktop client again. Don't worry, though, as any custom themes that you set up won't need to be re-enabled if you reboot your phone. Please check out our FAQs article on Substratum to learn more about how this works!

Part 2 - How to Install Custom Themes

First, you'll need to find a custom theme for your phone. Look for "Substratum" in the Google Play Store or check out some of the ones listed in this thread. Look for themes that mention support for Substratum or "OMS" as these are ones that are likely to work on your device. Themes that mention "legacy" or "RRO" won't work on your device.

As an example, we will be showing you how to install Baltic UI for Substratum. Please note that if you do not like this theme, then you are free to choose any other theme out there. I am merely choosing this theme for demonstration purposes as it is free and uses many of Substratum's features, making it a great candidate to show off Substratum's tools.

Download it onto your phone from the below Play Store link.

Once you've got it installed, follow these steps to install it:

  1. Open up the Substratum application.
  2. Look for "Baltic UI" in the list. Select it.
  3. There are two ways to install this theme. You can either tap the toggle near the top that says "select to toggle all overlays" which will check every overlay in the list, or you can pick each overlay one-by-one. Note: the themer currently recommends that you do not select the "System UI QS Tile Icons" or "System UI Status Bar Icons" overlay in the list, until he is able to fix them. Always check the Play Store description of any theme you install for theme-specific instructions!
  4. Pay attention to some of the options listed underneath some of the apps. For example, under "Android system" there are 3 dropdown menus for the accent, primary, and background colors of the Android framework. If you expand the dropdown menu, you can pick from a number of options to customize the theme.
  5. Once you've picked the app(s) that you want themed, tap on the paint roller floating button in the bottom right.
  6. Tap on "Build & Enable." You will see a screen telling you which themes are being compiled and installed. After a short time, it should complete without error.

After a few seconds, the theme will compile, install, and immediately be applied. Enjoy your new theme!

Part 3 - How to Uninstall Themes

  1. In case you notice something that looks weird, or you want to disable the theme to try another one out, then go back to the main Substratum page and open up "Recovery" in the sidebar menu.
  2. Tap on Restore Theme.
  3. Select either Disable all enabled overlays or Uninstall all installed overlays. Choosing the disable option will leave your themes compiled and installed, but they won't be applied anymore. Choosing the uninstall option completely removes them from your device. Either option is fine if you want to fix a broken theme!

Part 4 - What can I do with Substratum?

We have a series of tutorials aimed at showcasing some of the cool things you can do with Substratum that aren't just themes. Now that you know how to basically set up the Andromeda service and install a theme, try and follow some of these guides!

Conclusion

The best part about Substratum is that you aren't limited to just a single theme. As you can see, we are able to enable one or all of the overlays in the theme pack. You can take advantage of this and even mix and match Substratum themes from the Play Store. So you can have one theme pack that tweaks Hangouts while another theme pack tweaks Gmail, for instance. It's totally up to you how you want to theme your phone!

There are even other nifty, more advanced options in the Substratum app such as Float UI and the ability to set theme priorities. You can play around with some of these, but they're aimed at the hardcore themer who wants total control over how their device is themed. If that describes you, then try them out!

Keep up to date with the latest Substratum news on our Substratum forum or by following the XDA Portal using the XDA Labs app.