In industrial DC ccts white is positive and black is negative. In AC black is hot and white neutral. Plenty of confusion out there when electricians wire DC.
For 12Vdc I'd stick with white positive and black negative/common/ground
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)
1984 Fast/Nicholson 345 "FastForward"