In the original Star Wars trilogy, it is well established that the good guy spacecraft (blockade runner, Falcon, X/Y/A/B-Wings, etc) fire red blasters, while the bad guys favour green (Star Destroyers, TIEs, Death Star). However, in the prequel trilogy this association was flipped, with the good guys shooting green (Naboo starfighters, Republic gunships & other craft) and the bad guys red (droidekas, Vulture-class starfighters, Trade Federation stuff).
In-universe, the explanation I've seen given is a difference in quality of the Tibanna gas used to produce the blasters, but what I am looking for is an out-of-universe answer as to why the colours were flipped.
None of the behind-the-scenes material I've seen or read (and I've seen and read a lot of it) has ever seemed to mention the colour change at all. Was it simply an oversight on the part of George Lucas and the visual effects teams, or does someone know of a reason why it was explicitly changed?
Note that this question is related to the colour of spacecraft blasters, not the colour of lightsaber beams or hand-held/ground-based weapon blaster bolts.