You can switch the TOOL app screen between color display and monochrome display. Outdoors in bright sunlight, the monochrome display provides better readability than the color display.
To switch between color display and monochrome display
Hold down the TOOL button for about three seconds.
You can use any of the following operations to return to the color display; Hold down the TOOL button for about three seconds; Tap the touch screen; Swipe in any direction.