San Francisco’s City Hall has been lit in various colors for years , but recently to celebrate the 100th birthday of City Hall, a new lighting system was installed. The old system was installed during the mid-1990s, following damage from the 1989 Loma Prieta earthquake. City workers climbed onto the balconies, ledges and roof of City Hall to install colored gels on every single light fixture, costing $5,000 each time the color scheme was changed. This new lighting system has far more color choices and is much easier to operate and was paid for with $2.5 million in private donations and city funds. The 220 exterior light fixtures — each weighing 70 pounds — now have LED bulbs, making them more environmentally friendly. They no longer require gels but instead are programed using a computer system in the basement of City Hall. Now, they can be turned on with the flip of a switch.
Social media has brought the expressions of color to a worldwide audience: Purple to mourn the death of Prince. Rainbow colors for the Pride Parade. Red for World AIDS Day. Red and green for Christmas. Red, white and blue for Election Day. Images of City Hall glowing the blue, white and red of the French flag were displayed to commemorate the Nov. 13, 2015, terrorist attacks in Paris, a sister city of San Francisco.