Just as a follow-up, I decided to go with light blue for the prop labels, and happily a sheet of Techmod Spitfire stencil decals included a whole bunch of disks in pink and light blue with various markings. I used the ones with a “B” which looks rather like the ones in the photo of FY-V. I also reshaped the prop tips to a more rounded configuration as shown in the photo.

Thanks, everyone, for the discussion and information.
Pip