I'm so unused to blue rigging that each photo of your progress takes me a few seconds to process - that's not a comment on your rigging skills, just of my ignorance of the type!
A question was put to Richard Alexander from Wingnut Wings - his reply:
"Yes the structural rigging wires (but not control cables) on French WW1 aircraft were very frequently painted for protection. The favourite colour for painting anything metal on French aircraft at the time was blue. You can still find blue rigging on we preserved and restored WW1 French aircraft like Caudron G.4 at the Smithsonian".
It may be only certain French aircraft had blue rigging, although some photographs apparently show a mixture of blue and natural metal and others with blue fitting but natural metal wires.
I've gone for blue rigging as that's what is shown in the WNW colour plates in their instruction manual.
Also other notable artist, such as Bob Pearson show blue rigging.
The French also painted the edges around wings and tail unit on many aircraft with colours such as blue.
Right or wrong, I'm not changing it all now

Mike