Red wire, black wire and white wires

I believe there is a sorta standard. For 40 yrs, every 12v assesory you will ever buy has either black and white, or red and black for power. The red and black is always pos. I call that a sorta std. If you would install a black/white cable using the white as pos it would be wrong. Same w/ a red/black cable, a black pos would be wrong !