AI manual
"The next screen will prompt you to turn on or off Lunar Cycle for this timer. This feature will slightly dim or brighten the LEDs to simulate a full moon, half-moon, etc. based on the day of month. You would probably never use this feature for timers set up during the daylight hours. It is more appropriate for use with a night timer when LED intensities
are set very low or completely off."
However you can run the intensities at whatever is pleasing to you, part of the allure of the module IMO. However in looking at some of the night dive pictures available I have seen that the water is very blue when not illuminated by flashlights but rather by the moon and stars. So that is why I picked to have the white light off. Again personal preference.