Night Shift and Low Power Mode work together on iOS 9.3.2 beta 2
With Night Shift enabled, not only are the bright blue colors gone from the screen, the display is shifted to the warmer end of the color spectrum. The result is a better night sleep for the iOS user, and more refreshed eyes.
Sometime during the beta testing for iOS 9.3, Apple inexplicably made it impossible for Night Shift to work when the Low Power Mode is toggled on. Since both features would seem to be used mostly in the evening hours, (Low Power Mode would be turned on later in the day when battery power most needs to be extended) this move prevented Night Shift from being used when it was needed the most.
After a workaround using Siri was discovered that allowed Night Shift to work with Power Saving Mode on, Apple made the necessary fix with a server-side correction for iOS 9.3.2 beta 2. So now, when it is late in the day and your iPhone is running on fumes forcing you to use Low Power Mode, you still will be able to enable Night Shift to rest your eyes, and help you get a good night's sleep. Once the sun rises, blue returns to the iPhone and iPad screen along with colder colors.