I wouldn't bother with colored lights--I used to use them (red on left, green on right); but they're not nearly as bright as white; and quite honestly at a distance the white strobe would outshine the other lights anyway; unless it was directly sideways to you. But unlike most aircraft (especially large fixed wing); you're not going to get any direction information; as the lights are spaced so close to each other on a small object and the
P4PV2 can fly any direction regardless of which way its facing.
I use four white ARC IIs on my
P4P: one on top; two on each side forward of the side sensors (only used in daylight while in tripod mode), and one in the back just between the battery and the sonar sensors. The lights on top seems to have no effect on the GPS--at least with the number of SAT locks.