The Roddenberry link to the same keyboard Norm showed was dead for a while, but they fixed it recently, and here is a direct link to the (very expensive) keyboard and aluminum housing. The textured taupe finish is meant to be evocative of TNG bridge computer consoles. Apologies for the self-promotion, but I didn't want to not answer your question.
That is why the legends on this set are printed using a dye sublimation process (part of why it costs so much). With this process, the ink is deeply infused into the plastic using heat vaporization of the ink, rather than simply being printed on top of the plastic, making these about as durable a keycap printing as you can get. To @PaulMmn's point, I would say that it is actually debatable whether ABS doubleshots or dyesub PBT caps are more durable over time, as the ABS tends to shine readily. This fabrication process by this company is used on high-traffic phones in call centers, on cash registers, and in lots of other industrial electronics, so it's really designed to take a lot of wear. The Galaxy Class set should last nearly a lifetime.
Here is a bit more info:
Dye Sublimation a very durable solution for printing complex and multi-color graphics on parts, all within a single print cycle. The process is limited to printing dark colors on a lighter substrate.
A leading supplier of digital video editing keyboards found Signature Plastics’ sublimation printing process the right solution for their complex graphic requirements. Using this process, an entire keyboard containing multi-colored graphics can be printed within a single print cycle.