Interesting info. I use Aqua Signal 'map/chart light' throughout my boat for 'night'. These are simple white lights with 'irises' that mechanically allow the light intensity to be turned 'way down'. I have long preferred these over all other adjustable/variable lighting .... and they are 'white' light. I have some 'red' lights and usually turn them off as they have always seemed to distort my night vision; although the monochromatic red or green LEDs do seem to work if very low powered/output.
Along with the AquaSignals I also use 'cigarette lighter' lights .... electic cigarette lighters with (optional) very small white incandescent lights in the 'handle'. They show very little light but *just enough* to visualize the cabins/compartments interior on the 'blackest' of nights. They fit into the typical 12vdc 'cigarette' bayonette.