The LED blinks green and red in air?

[senkisemmi]

Hi, all!
The LED of my DJI Ryze Tello flashes green and red (the color changes with a period about a second). It happens anytime when the copter is in air - even when it hovers motionless. The battery is new, its level is normal, the wi-fi signal is strong. The program (the official one) does not complain about low light levels either.
Could anybody explain me, what does it mean?

 

[volate!lo]

you have (almost?) reached the user-defined altitude limit. Increase the limit and the blinking is gone

 

[senkisemmi]

Oh, that's what it was! I test the copter at home, so set the maximum altitude to 2 m, not to crash into ceiling. Really, setting it to 5 m removed the red blinks. Thank you so much.