Perhaps it's been whipped to death, but....If I make my own powered unijoiners for a DCC system, How do i know which rail should be Blue wire and which should be White wire? I will have approx 21 blocks both rails insuated. Some track power will be to KATO feeder track, other will be my own. Does it matter? it seems to me if the KATO feeder has the blueon the right, and the next block I put the blue on the left i will a bunch of reverse polarity. Yes? Please help. I am at the wiring phase of construction.....Thank you very much. J&MH Railroad.