For years, Hong Kong’s neon signs have played bit parts in its cinema, providing a soaring red backdrop for a rooftop romance in Clifton Ko’s 1986 “Devoted to You” or backlighting the blonde wig of a mysterious Garbo-esque figure in Wong Kar-wai’s 1994 “Chungking Express.”

Now the signs are starring in their own show online.

They are the subject of the latest pop-up exhibition by M+, Hong Kong’s new visual art and culture museum, before the museum opens its physical doors in 2017 as part of the West Kowloon Cultural District, now under construction.

This is M+’s seventh pop-up show, but its first online. Running until June 30, it is a tribute to neon signs and their place in the Hong Kong cityscape and imagination, from their heyday in the 1970s and 1980s to their fade-out in the last decade as LED signs took over.

Posted to NEONSIGNS.HK, and updated continuously, it showcases M+’s ambitions to blur artistic disciplines and to be global as well as local. The website includes photos, essays and slide shows by writers, artists, photographers and academics living and working in Hong Kong. A 12-minute video, “The Making of Neon Signs,” features interviews — in Cantonese with English subtitles — with longtime neon sign makers and takes viewers into their workshops.