Bart,
Have you had a look at the photo archive picture ? (or ordered a copy ? )
http://mikan3.archives.ca/pam/public...&total_items=1
It looks to me as if the number has been painted over an earlier marking and also as if the tank colour has run due to fuel spillage. I can't see a coloured background.
I'm a bit puzzled because the Norton transfer appears intact suggesting that there hasn't been a repaint (and looks white like the census number rather than gold).
Rich