The main window as well as the readycheck window (if enabled) of oRA3 are skinned to match ElvUI's theme.
Both ElvUI and oRA3 need to be installed, this is just an appearance modification :)
v1.0 has been tested with ElvUI 5.99 and oRA3 r594 for WoW 5.2.0
Installation / Usage
Just extract to your addons folder, nothing further needed.