I've used the clear decal paper on a white deck method and it worked quite well for yellow and grey lines with white lettering, in my case.



The problem was getting the deck colour right - inevitably the shape and size of the decal is slightly off so you end up having to touch up the edges which doesn't then match. I ended up painting over almost all the basic colour to get an acceptable but not perfect effect.

Unless the markings are really complicated, I'd be inclined to just build them up from basic white lines, circles and letters.

https://midlandshipyard.blogspot.com/2019/11/home-made-water-slide-transfers.html