Rising 75m above low-rise Amsterdam, the landmark Hotel Okura Amsterdam building is visible from afar both day and evening. Each night the roof's perimeter is illuminated by LED lights, which change colour depending on the barometer's reading for the following day. Blue lights mean a bright, sunny day is forecast. Green lights mean bad weather is on the way. 'White' (more like a pale-pinkish colour and the most common) means the weather will be changeable.
The lights also change colour on special occasions, producing a variegated rainbow effect for Amsterdam's Gay Pride Parade and New Year's Eve, and, of course, turning orange for King's Day.