Printing objects with different color text is a pretty neat effect (see previous post regarding printing with multiple colors.) You do have to be careful with the size of the letters though, as they quickly lose definition. The following are three versions of a faceplate for an overly complicated benchtop power supply I put together:
The lettering on the first one looked pretty crappy. For the second version I switched to a 0.25mm nozzle, so I was able to get much better definition but it took for-ev-er.
Also I hadn’t installed the USB port when I took this picture. I have since installed it and it looks dope.
I ended up having to reprint it a third time because the components didn’t fit right. At the same time I also made the letters even bigger and switched back to a 0.4mm nozzle. The final version had 8mm and 11mm lettering according to Fusion 360.
CONCLUSION
On a 0.4mm nozzle, don’t go smaller than 8mm height. When using a 0.25mm nozzle, don’t go smaller than 5mm. This also depends on your font. I was using big chunky letters, so if you used something more delicate you would have to go even bigger, or use the smaller nozzle.
BONUS CONTENT
If you print something flat-ish, leave it on the print bed until everything has cooled down to room temperature. I took the faceplates and the body of the power supply off too early and they warped pretty badly.