Night light depends on a feature called a "gamma ramp". That feature is not supported without at least a proper KMS graphics driver. That should be available for Raspberry Pi 4 in kernel versions 5.10.7 onward, in theory.
Night light depends on a feature called a "gamma ramp". That feature is not supported without at least a proper KMS graphics driver. That should be available for Raspberry Pi 4 in kernel versions 5.10.7 onward, in theory.