I've noticed DJI makes their lights red in FRONT and green in the BACK. I presume these are supposed to be similair to aircraft navigation lights? Anyone know why DJI didn't make the lights red on LEFT side and green on RIGHT side?

Heck of a good question. The standard FAA navigation light layout would be helpful for orenting the pilot as well (covered by the Advisory Circular 20.30B and sections .1835 - .1401, parts 23, 25, 27, and 29 of the Federal Aviation Regulations).

I wondered about this as well, maybe because of only 3 lights?

ya i wish they used the standardards already in place but to be honest it's not terrible and the 2 red LEDs in front have helped me figure out which way i was facing in the dark.. so its usable just not ideal..