He talked about how the wiring schematics were a maze, made worse by using only non-labeled gray and black wires with connections and mounts that were the same color made of the same material.
The exterior being gray makes sense - harder to see with human eyes. But internals? They should be massively contrasting colors for every single series of pieces to be removed so you can just follow along by color.
1. Cost savings when buying.
2. There are hundreds to thousands of wires in an aircraft, but there are NOT hundreds to thousands of different colors of wires (even if we allow for stripes, etc) that are readily distinguishable to an overworked airman hunched over in a dim, cramped avionics bay trying to fix a plane that needs to take off for a mission in an hour.
If you are lucky, the wires are numbered. But even if they are, you typically identify a wire by its connector pin and PRAY that the fault isn't a break somewhere back in the wiring harness.
Sometime before that, he got a lot of flak for having neglected one of the standing rules, to label everything as you take it apart and put it back "the way you found it". He decided to break it down and put it back the way the technical documentation said it should actually go. This seems to be part of the reason his radar performed better than the others after teardown maintenance.
[1] https://www.google.com/search?q="биррен"+зеленый&udm=36&tbs=... (search for Russian for "Birren"+green in 20th century books)
My two guesses are that it was colored like that get the pilots feel like they were in a particular environment - a familar but not exactly private or comfortable one. It's a cultural thing like if you paint a bus yellow, Americans will think of a school bus, but most other people won't.
My other guess is that they only made certain kinds of dye, and its very well possible the same factory made it that made it for bathroom tiles. In capitalism, if you don't have orange paint, for example, some company will just start making it if there's a demand.
In communism, if nobody makes it, then it's not available, until and if some comittee decides that it should be made.