How to Change the Default Device Theme in Android O

A new feature in the first developer preview of Android O shows that we might actually have the ability to install and change themes.

Android has a number of ways for us to customize the look and feel of our devices. We’re given the ability to completely change various aspects of the user interface (like changing the Lock Screen and Home Screen) with 3rd-party applications. We can change the Home Screen and Lock Screen wallpapers, and then there are some OEMs that actually let us customize the Navigation Bar icons.

For those with root access, we can even take this further with various theme engines.

CyanogenMod was one of the first big theme engines for Android, but lately it has been surpassed by Substratum. Substratum is actually built upon an older theme engine called Layers, which utilized the RRO framework within Android. This was created by Sony, submitted to Google and is now in place within the AOSP code base. However, a new feature in the first Android O developer preview is making many believe that this will finally be accessible without needing root access or a custom ROM installed.

So let me show you what the Android O Device Theme is, and how it works right now.

Android O Device Theme

1. Launch the Settings application
2. Tap on the Display option
3. Tap on the Advanced option
4. Scroll down and tap on the Device Theme option
5. Tap on the Android O Device Theme of your choice
6. Tap on the Restart button to confirm the change
7. Wait for the device to reboot back into Android O

Explanation

Now, we’ve actually had access to an inverted theme in the past. It was called Color Inversion in previous versions of Android and was generally located in the Accessibility section of the Settings application. This was always labeled experimental with a note saying it could impact performance. What it did was attempt to make any light colors dark, and any dark colors light. This has never been a very popular feature from what I can gather.

So Google may have simply moved this feature from the Accessibility section to the Display section of the Settings application. Or, they might actually be giving us access to the theme engine that is baked into the core Android OS. We’ll just have to wait and see how things turn out before we can know for sure. For now though, we can access this feature by launching the Settings application and then tapping on the Display option.

We’ll then need to tap on the Advanced option to expand some more hidden features here. Scroll down and look for the Device Theme option and go ahead and tap on it. By default, this doesn’t have any option selected (at least it didn’t for me), so tapping on either of them will prompt you to reboot the device. For my and my Pixel XL, the theme it was using by default was the Pixel theme (even if it wasn’t selected at first), so tapping on it didn’t change anything after a reboot.

It wasn’t until I selected the Inverted option that I noticed some UI elements were a different color than before. I only noticed a change to the Quick Settings panel in the first developer preview of Android O. This could change in the future though, so it would be a good idea to watch this feature and see how it evolves. For now, choosing an Android O Device Theme will simply let us change the colors of the Quick Settings panel, which still could be nice for those who enjoy a light theme.