Hi Simon,
OK, the question of WNr. is open. I saw there digit 1 or 4. I will change to 4

but the color does not seem like yellow to me...

see attached photos. What do others say?
when you compare stencil color on the engine and the band color, seems the same, also the WNr color and the tail color...I would say white...as well underwing cross vs. band colors...
regards
Peter