The question was asked a week or so back: what colors were used for the stripes on the u/c doors, and what was the significance.
The significance (load-bearing limits) was answered, and I attempted to get a straight answer from my friends at the model club meeting yesterday.
Too bad no-one there is an expert (why are German aircraft so popular???). In any case, the consensus was that red (lower) and blue (upper) bands were used as standard, and that as the loads were increased in the same type of aircraft, that some white or yellow might have been allowed to creep in between the lines - or maybe just the plain aircraft wheel door color. Variation between Mitsubishi style (straight camo line on the Zero) and Nakajima (curved camo line to tail) might also be a cause of discrepancy.
Sorry, that's all I could come up with at short notice, if more info surfaces, I'll be sure to post it.