There's a howto somewhere on fixing the rubber rings(?) in key cap mechanism somewhere nnline, so they must be switchable. You could also go the down and dirty method using stickers and a couple of KCHR resource hacks in Resedit.
https://68kmla.org/forums/index.php?/topic/11915-simple-resedit-pb-keyboard-hack/
The gray is killer, but they munged up the enter key. Do those boards have an extra key or is the vertical enter key a convention in Europe? I've studiously avoided that implementation since my first VT-101 layout KBD purchase, a MAC-101.
And the ¨ are only for Ü Ö and Ä … Can't type my name correctly