Silicone keypad is ok, but i would go for 3d printed blank keypads.

Blank keyboard lets users make their own keymaps without having to ask you to make additional ones. The appearance point of view is not that important as it's really for personal use and sole purpose of usability. Of course it would be nice to have fancy keylabels, but I really appreciate functionality over the appearance.

If the 3d printer resolution is good enough, you could also print the keylabels in relief.