A Brief History of Theming: From OEM Themes to RRO Layers

A Brief History of Theming: From OEM Themes to RRO Layers

Uncover the various Layers available to a Themer

The root of Android’s charm as a platform lies in its satisfyingly freeing open-source nature, which gives manufacturers, third-party firmware developers, and even end users a free rein over their device.

While the intricacies of open source code will undoubtedly come off as gibberish to the end user, the most obvious and subsequently most appealing manifestation of open source firmware is the limitless customization options it provides, allowing users to truly make their phone theirs. Given the amount of time people spend glued to their smartphones these days, having every aspect of the system resonating with their personal taste and acting as an extension of them pleases almost every personality that cares enough to put the (now minimal) work on it, and it makes the operating system a delight to use.

History of Theming

widgetlocker apk

The epitome of theming, back in the day

For the average user, a simple wallpaper change – possibly a live wallpaper, an icon pack and maybe a widget or two were the limit without diving into system modifications, but as Android matured and the competition between OEMs heated up, consumer needs started being realized and customization arose as a feature that most users craved. Gradually, some OEMs began bundling system themes along with their firmware, but the lack of flexibility and attention given to OEM themes created a void, a void that was filled with Themer by MyColorScreen last year. Arriving on the scene amidst a flurry of excellent marketing, Themer remains all the rage for homescreen theming, giving users one-click access to thousands of beautiful and elegant themes. However, some OEMs stepped up their game simultaneously, with Sony, Samsung and HTC making formidable pushes in the themes sector as of late.

However, for power users, styling an Android smartphone can take on various forms, from simple changes like custom launchers and Android packs, to more serious root-enabled modifications such as custom fonts and system themes. While the former options are fairly straightforward in their own stead, going on to be replaced by more finessed solutions like, the first step towards serious theming was the launch of the T-Mobile Theme Engine.

Designed and developed as a community project as opposed to being a T-Mobile exclusive feature, Theme Engine stepped into the limelight when it grew stable and useful enough to begin being packaged into CyanogenMod. This app allowed users to download theme packages in the form of APKs, and style a large number of third party apps, system apps, fonts, and more, simplifying a significantly complex procedure tenfold! As time passed, Theme Engine became an integral part of CyanogenMod and as of late, Cyanogen OS, and while it provided a solid solution, the community’s thirst wasn’t quenched, and a new approach titled RRO Layers surfaced.

Based of Sony’s internal RRO framework, the project overcame some of the theming restrictions that Lollipop imposed, and shot to fame soon after its launch, buoyed by simple theming and a tremendous community boost.

With themes playing a significant role in user satisfaction in today’s world, let’s take a quick look at the top theming options that let you make your device yours.

OEM themes


Sony has emerged as the leader of the pack when it comes to OEM themes, bundling multiple options with their firmware and opening up the Xperia Theme development process to third-party designers, even going on to create tools that simplify the theme creation process. Only this year did Samsung and HTC take major steps in this direction, with both manufacturers integrating themes into TouchWiz and Sense respectively, albeit opening up the avenue for third party themes through their own delivery systems as opposed to using the Play Store as a channel. While these OEM themes may not appeal to power users given their lack of granular control, their presence and ease-of-use delight the average consumer and boost customer satisfaction levels tremendously.



Despite not being a system theme platform per se, Themer revolutionized the world of Android theming, setting the stage for one-click themes that brought colossal variety to the user’s fingertips, with the simplest of steps required to switch between themes. Developed by the Android theming dedicated website, MyColorScreen, Themer took over the homescreen launcher experience, and with a simple and elegant flow, directed users to its theme repository, populated by community submissions, requiring a mere three steps from opening the repository to applying a theme. The attention received by Themer from third-party designers and its elegant user experience buoyed the app to fame, making it an unopposed favorite in casual theming.

CyanogenMod Theme Engine


Kicked off at T-Mobile as a community-targeted project, as opposed to a carrier exclusive one, Theme Engine functioned as a system app that replaced resources in the framework with custom ones bundled in the themes. Its efficient and systematic approach to resource replacement caught the CyanogenMod team’s eye, and soon after, it began shipping with CM builds, increasing in functionality and popularity as time passed. While Theme Engine remained a power user’s toy for a significantly long period of time, Cyanogen Inc’s. partnership with OnePlus and Yu and the birth of Cyanogen OS saw the powerful tool reach the hands the average user as well, fostering its popularity on both sides of the fence.

RRO / Layers


Runtime Resource Overlay was a solution developed internally at Sony for the functioning of Xperia Themes and for quick protyping, in the wake of Android Lollipop’s limited theming abilities. Recognizing its potential, a few developers worked together to make free the framework from Sony’s confinement and bring its infinite potential to custom ROMs. The ability of the framework to replace resource strings during runtime bring forth a number of hooks and methods that theme developers can employ, bringing flawless theming with granular control to the table. However, with great power comes great responsibility, and Layers, as the initiative came to be called, is balanced solely towards power users in terms of prerequisites and setup, but once setup, the Play Store and Layers app work excellently as a distribution channel and installation center respectively. Layers is in active development, and has recently gained Marshmallow support, and future plans include integration with all OEM ROMs as well.

Where Is Theming Headed?

The ‘make it yours’ tag resonates well with users, proven not only by the demand and success of themes on Android, but also by out-of-the box solutions like Moto Maker. Users want customization, they want flexibility and they want a free reign over their devices, and OEMs and Google alike are growing ever aware of that, and in a unexpected move, the Android M Developer Preview included unannounced support for Dark and Light themes, and startlingly, for RRO/Layers as well. Despite both features not being readily available in the final version for non-root users, their inclusion is proof that Google itself is paying attention this need, and future versions of Android will almost certainly include a system-wide theming approach that doesn’t require root. Until that happens, the top OEMs continue to iterate and polish their own solutions, and each passing day increases the quality and variety of the options presented to the user.

How did you get started with theming? Which is your favorite theming solution? Got any wonderful setups you’d like to show us? Let us know in the comments below!

About author

Faiz Malkani
Faiz Malkani

Faiz Malkani is a designer committed to creating memorable digital experiences augmented by delightful interfaces. He's been working in the design field for over three years and is proficient in experience design and interface design. He also codes occasionally, with Android and Frontend Web being his preferred platforms.