what colour is 12 volt postive ignition wire ?

use a D M M across the coil connection using 20 v DC scale range.

If you get a - sign 12v this just mean lead polarity is wrong way round ie the red lead is the negative, the black lead being the positive,this doe'snot harm the meter.
(what we are after is NO minus sign on the display screen)
if you get 12 v the one that the red meter lead is touching is the 12 positive connection, this is the colour you are after. could check this in a Haynes workshop manual in local library

wirecutterman
November 2009