while I am on LockScreen when I hold power button the power menu pop up with whole blue screen.. while on home screen or any screen I can see the background.
if you don't receive any similar issues so leave it. it's fine.
Nice Work, but I have only faced one issue while in LockScreen on Samsung Stock 5.1.1 when I hold the power button the background turns into blue one.. Video:
https://www.instagram.com/p/BD8kJ8JFWlH/