Just talking yamaha general wiring colours i would think for tail light to be on all the time it'd need to be a light brown live dc wire.
Don't dwell on my ideas though unless they fit.
I'm talking older models than yours.

"Just talking yamaha general wiring colours i would think for tail light to be on all the time it'd need to be a light brown live dc wire.
Don't dwell on my ideas though unless they fit.
I'm talking older models than yours."

It would, but actually connected to the blue wire/contact in the ignition switch - tail light wires are generally blue, black and yellow (brake).

GR8Uncle, in post #20 he says he doesnt mind the tail light being on all the time, which i thought blue would be via the mag, so only when motor is running.
But i'm 20 years behind haha & tired--so not reading the full story. All good.

i.imgur.com/Mdc5slx.jpeg Picture of newly painted tank & there are no decals that is all painted on.

Got lights working albeit a workaround , side light & tail light come on with ignition as do the instrument lights , headlight works with mag , Hi-Lo beam all ok as is on/off , parking lights work when ignition in the P position , battery charges ok with lights on and bike running . Probably not ideal on a 6v system but it is what it is .

Nice work!  Congratulations on a job well done!