This Xposed module restore LED functionality of Xperia devices when Stamina mode is enabled. Normally, when enabled, Stamina mode either disable the device LED or force it to show only white color.
1. Your phone must be rooted
2. Xposed framework must be installed first http://forum.xda-developers.com/showthread.php?t=1574401
3. Xposed library 2.2 is required
Install the module
Run Xposed Installer and enable the module Xperia Stamina LED
Reboot the phone