Depends on what you want to do?
I put Obstacle Avoidance "OFF" all the time(As I Have No Need of It) or at least keep it off at Take OFF and Landing !!! I have my Flight Mode to "Angle" Mode always, but again, at least at Take Off/Landing !!! Unless in Smart Mode and outside the 26' foot safety perimeter !.
If In Angle and good GPS and Satellites it will blink Purple/White constantly, If in Smart it will blink Green/White. The color codes sequences are to much to explain but are on the card provided in the quick start package that came with the H ! (Or should have been ! )