Ok, let's go and find a manufacturer!
I got another, more detailed information on swiss color coding. Until about 1970 Phases red (R), green (S) and dark blue (T). N yellow. PE yellow-red until the 1950ies, later yellow-green. Phase after fuse often red. Switched phase often blue or green. Got you the following colors to a light fixture: Green, yellow-green and yellow. 3way travelers often white.
In the ca. 90ies introduction of blue neutral, ban of blue phase. Yellow seems to have died out. Phases red, black and white, after fuse often black. Switched neutral whatever, for example green, travelers green as well.
