Hi all!
I have printed the raised text buttons and painted them. I found it hard to create a smooth surface on the black paint, and to get it uniform enough to have no light bleed. I'm now experimenting with doing a filament change for the recessed text buttons just as the letter starts to print. So basically I have a transparent filament base and then switch to black. It might work better with slightly more shallow recess because looking at the recessed letters at an angle distorts them a bit. I'll see if this is viable, changing to a 0.2 nozzle as we speak. The pictures below is the first test print with a 0.4 nozzle.
Here is the first version that I printed upside down with a 0.2 nozzle and 0.2 Line width with a filament change to white for the "base". Bed leveling is crucial of course as well as dialling in the flow rate for the first layer. A layer of clear spray lacquer on top would probably help to smooth it out further and give some protection to the white recess that otherwise probably will fill up with gunk. I like the smooth surface and I think this might be the best possible way to do it with a 3D printer. I'm currently printing with a small negative expansion on the frist layer to get even clearer text as the first layer always expands a bit. 0.2 Line width on a 0.2 Nozzle is not great so I might tweak further to maybe 2.2 but for the smaller text especially on the action buttons I want all the resolution I can get.