If you are experiencing issues where some elements** of a watchface, widget, datafield or application disappear after configuring colors, you are probably setting it through an old version of Garmin Express.
SOLUTION:
Upgrade Garmin Express to version 4.1.11.0 or later.
Earlier versions of Garmin Express had a bug that caused the wrong values to be saved to the devices, resulting in colors becoming black, or some other unexplicable color. Elements whose colors have then incorrectly been set to black then "disappear" against a black background.
Developers should inform their users of this, either by linking to this thread, or stating it on their app descriptions.
**elements could be any color configurable object that is displayed on the screen, like the time, the date, step counter etc.