(1) "Technicolour" (or "Technicolor" in American English) was a technology used to shoot and develop color film in the 20th century. (Before Technicolor, most films were in black and white). Technicolor was later replaced by superior color technology, but its distinctive coloration remains influential in film even today. (2) It sometimes gets idiomatically used to refer to the color in a modern movie, although this isn't very common. I can't tell if the quote you've given is using in in the idiomatic or literal sense without more context.

"Technicolor" literally means "the trade name for the dominant process for making color cinema movies from maybe 1940 through 1960." When people say "in Technicolor" or "in glorious Technicolor" they mean "very bright, showy, strong colors." Technicolor was only used in theatres. It was far too complex and expensive to use in home movies. "Technicolor color consultants" guided production and made sure that EVERY Technicolor picture was bright and colorful. I don't know why, but "In Glorious Technicolor" was actually a stereotyped phrase, used on movie posters and in advertising. Never "beautiful Technicolor" or "lovely Technicolor" or "bright Technicolor," always "glorious." The phrase became a catchphrase and then almost a joke. Just as someone might say "Susan is like the Energizer Bunny" (she never gets tired, like the toy mechanical rabbit in a battery commercial), they might say "that sunset was so beautiful, it was like glorious Technicolor." In the 1950s, before color TV, the bright colors were actually a big reason for going out to the movies--others being the big screen, the stereophonic sound--and the air conditioning!