A small update and discovery of a technique from my past, when I was working in a signage company when I was a student. I've got masks for the national insignias and numbers – all of them has a white background, so I've pre-painted these areas with white (because I don't want to deal with applying a white color over the darker background), and I've got a question – how to transfer a foil from a paper to a model? And the answer is – use some weak adhesive tape (that's what I was doing in a workshop, building outdoor signs). Here, I was using some adhesive tape for paper.
The first step is to remove everything, leaving only the needed elements:
Next, apply the "transferring" tape:
Carefully remove a paper:
Arrange items on a surface (due to a semi-transparent tape it's not that hard, and it's not a decal, so you have a lot of time):
Remove transferring tape:
Then, I've applied a dark blue color on insignias, mask the roundels, and next is the base color:
