At the end of september google officially released a dark theme for Maps application. However the updates are only available to few users Now google officially announced that the update will start rolling out to more users.
Here How to activate Dark mode on google map
setting the dark theme is very easy you just have to open setting in the map application. in the setting tap on theme and select always dark or dim the light (enter dark mode )when you nevigate explore or do various things with the maps if your not confortable with it just go to setting then themes and select always in light theme.
