Each winter, since 2009, the transport society of Budapest decorates its trams with more than 30 000 sparkling white and blue LED lights for Christmas. If the tram drives fast, it will turn into a wagon made of spurts of lights.

An injured woman is pictured near the Blue Parrot nightclub in Playa del Carmen, Quintana Ro state, Mexico where 5 people were killed, three of them foreigners, during a music festival on January 16, 2017. A shooting erupted at an electronic music festival in the Mexican resort of Playa del Carmen early Monday, leaving at least five people dead and sparking a stampede, the mayor said. Fifteen people were injured, some in the stampede, after at least one shooter opened fire before dawn at the Blue Parrot nightclub during the BPM festival. (Photo by Victor Vargas/AFP Photo)

Bystanders look on as workers arrange silver blue fabric, part of the process of wrapping L'Arc de Triomphe in Paris on September 13, 2021, designed by the late artist Christo. Work has begun on wrapping the Arc de Triomphe in Paris in silvery-blue fabric as a posthumous tribute to the artist Christo, who had dreamt of the project for decades. Bulgarian-born Christo, a longtime Paris resident, had plans for sheathing the imposing war memorial at the top of the Champs-Elysees while renting an apartment near it in the 1960s (Photo by Geoffroy Van der Hasselt/AFP Photo)

Winner. “I took this vertical image in the Quarry Bay district of Hong Kong during the dusk ‘blue hour’, when there was a perfect balance between the ambient light in the sky and the artificial lights of the high-rise residential buildings”. (Photo by Jatinder Heer/The Guardian)

In advance of Fleet Week performances, the U.S. Navy Blue Angels and Team Oracle aerobatics pilot Sean D. Tucker fly over the San Francisco Bay during a photo flight on Thursday, October 5, 2017. (Photo by Noah Berger/AP Photo)

A member of the Air Force's Wings of Blue Parachute Demonstration Team salutes as he jumps out of an aircraft, during the opening ceremony of Aviation Nation 2017 Nellis Air and Space Expo at Nellis Air Force Base, Nev., November 10, 2017. (Photo by Senior Airman Kevin Tanenbaum/Reuters/U.S. Air Force)

A coil-shaped Helix Nebula showing a fine web of filamentary “bicycle-spoke” features embedded in the colorful red and blue ring of gas. At 650 light-years away, the Helix is one of the nearest planetary nebulae to Earth. A planetary nebula is the glowing gas around a dying, Sun-like star. (Photo by Reuters/NASA)