Been thinking about this for a bit already but don't have a 3d printer for it.
Sticker labels for keys (left) do look quite good, but quickly are coming off.
Some friendly being printed us a test batch of keys using dual filament printing.
Looks quite good for a first attempt but certainly can use some improvement

Picture of two Airbus MCDUs laying on a bright surface, the left MCU has stickers for the marking of the keys, they are quite clearly readable but some are already coming off.
The right MCDU has the keys printed from white and black filament. The arrow keys and bigger letters are clearly readable but the menu keys with smaller font size are not that legible.
0

If you have a fediverse account, you can quote this note from your own instance. Search https://chaos.social/users/flyfly/statuses/114478557579756972 on your instance and quote it. (Note that quoting is not supported in Mastodon.)