Now with Arcus support, and 3 more color variations, both with Light and Dark Notification versions
Check this community to download Arcus: https://plus.google.com/communities/105739351821425192942

Please NOTE that even if supported, CM13/14 Nightlies or Betas can have bugs and could make your device unstable / unusable.
Make a Backup before make any changes and keep in mind that they are not stable builds!

FEATURES:
With Atomic Blue you can feel a unique, professional user interface, rich of crisp colors and vector graphics, always different,
that will customize your phone or tablet with a per-pixel created UI,
and the inclusion of many features like:

- Atomic Style on all the main applications, like Dialer, Browser, Downloads, CM Music, CM File Manager, Google Now and Google Keyboard.
- Unique graphics all over the system, your apps will taste a new look.
- New fonts, icons and a custom wallpaper with different color palette for every variant.
- An exclusive bootanimation made from scratch with a "Material MoGraph" in mind.
- Rock solid compatibility with CM, Dirty Unicorns and Pure Nexus Roms.

FOR NEWS AND UPDATES:
Join the SteelDesigns Themes & Apps Community to try new Beta Versions, receive support and updates about the project: http://goo.gl/UTbB0x
Follow the SteelDesigns page on Google+ for the latest news: http://goo.gl/YXsmZe

REQUIREMENTS AND INSTALLATION:
You need an unlocked device with a CM Based ROM with the CMTE (Cyanogenmod Theme Engine) to use this theme.
1. Download the app and install it (you can't open it)
2. Go to Settings>Themes (or the Themes section of your custom rom)
(If you don't have this option you are using an unsupported rom)
3. Select Atomic Blue, choose what you want to theme and apply!

IMPORTANT:
Please report any bug before rate the theme, you will help me to continue to make this theme better, thanks!
Instead, do a search with Google to unlock the potential of your device,
or ask for help in the SteelDesigns Themes & Apps Community.

// Option A //

To download Atomic Blue - CM12 CM13 Theme mod from HappyMod.com.
You need enable the option "Unknown Sources".
1. Click on the above link to download Atomic Blue - CM12 CM13 Theme mod APK.
2. Save the file in your device Downloads folder.
3. Now tap on Install and wait for the installation to finish.
4. Once it is done, open the game and start playing it right away.

// Option B //

To download Atomic Blue - CM12 CM13 Theme from HappyMod APP, you can follow this:
1. Open your browser and download the HappyMod APK file from HappyMod.com - the only official website of HappyMod.
2. Open Android Settings and go into Privacy or Security.
3. Tap the option to Allow Unknown Sources and enable it.
4. Go to your Android downloads and tap the APK file.
5. Follow the directions on the screen to install it.
6. Search Atomic Blue - CM12 CM13 Theme in HappyMod App.