Lighthouses are usually white. They used to rotate (sweeping the beam) but tend to flash now I think. Nautical charts show the elevation of the light, the visibility ranges and the pattern of on/off (eg Fl (2) 10s 41m 17NM). Some lights are sector lights, so red/white/green depending on your position, they indicate if you are in the correct approach channel.

It can be really confusing approaching a port at night. Never mind the city lights behind, and the cars driving about. 20+ lights flashing at different rates in the dark, some of them disappearing for seconds at a time. Oh, and if you turn your light on to refer to the chart, there goes your night vision!

Boat masts above 25m also have blinking red lights for the low flying aircraft (I guess its a bragging point)