The following is off subject of wire color. It sounds like the OP is trying to improve trailer braking performance, so I'll tell my story of the same. We upgraded from Lippert 4400 lb. axles with 10" drums to Lippert 5200 lb. axles with 12" drums trying to improve brake performance, but it was still not enough. Talking to Dexter support I got the feeling that the magnets were all about the same, but that the brake linings became more aggressive as the axles went on up to 6000 and 7000 lb. capacity. So I had Dexter 7000 lb. self adjusting backing plates installed in my axles. I guess I have them strong enough now since I can skid them on wet surface and in a panic stop two months ago, I ripped a rear spring hanger half off. Funny thing is that the self adjusters still don't get the brakes as tight as the recommendations for manual adjustment--the wheels will spin several turns. But at the same time, they probably don't let the adjustment get extremely loose.