LeEco Smartphones comes with Customized EUI which is based on Android. The EUI is quite simple and colorful, however LeEco users can now also taste Android Vanilla UI on their devices.
Thanks to Xda developer "zyberkiddy", who made a Xposed module named LeEco EUI Moder which lets you theme and customize a number of features present in LeEco’s EUI version 5.8.
For now, this module will customize your Smartphone's Lockscreen, Quick tiles, Notification Panel and few more things. The Developer is working on more upgrades on this module.
Give it a shot- LeEco EUI moder