Enabling Dark mode in MoneyWiz will change MoneyWiz color scheme to darker colors, making it easier to work with -- especially at night. You can enable it from MoneyWiz Settings > Theme. There are two options to choose from:
Light -- force light mode.
Dark -- force dark mode.
There's also an Automatic switch. Enabling this will make MoneyWiz adapt to the device-wide setting (set in System Preferences > General).