George........never heard of color coded sparkie wires. I have seen tinted clear insulation on display hot-rods. They ain't worth 'chit!!! The sparkies jump right thru the insulation and dance the nite away.
The original 9N sparkie wires were covered with a "braid" that could have been color coded as the rubber insulation for sparkie wires was NOT very good. Unless yer a sphincterly challenged originality inspector, I would NOT waste my $$$ on color coded wire.
The important thing, whether color coded ...or... black or yellow, is the center conductor is stranded copper wire and NOT modern resistive string. .......Dell, yer self-appointed sparkie-meister