Colours of Ostrava, or simply Colours, a multi-genre event, is the biggest international music festival in Czechia and one of the biggest in Central Europe, held every summer since 2002 in Ostrava, the third largest city in the country. Colours features 16 stages, including 4 big open-air stages, 6 indoor stages, a theatre stage, a workshop stage, a kids' stage, a cinema, and live discussions. It features performers from all major popular music genres as well as avant-garde music and world music.

Ostrava is a city in the north-east of the Czech Republic and the capital of the Moravian-Silesian Region. It has about 280,000 inhabitants. It lies 15 km (9 mi) from the border with Poland, at the confluences of four rivers: Oder, Opava, Ostravice and Lučina. Ostrava is the third largest city in the Czech Republic in terms of both population and area, the second largest city in the region of Moravia, and the largest city in the historical land of Czech Silesia. It straddles the border of the two historic provinces of Moravia and Silesia. The wider conurbation – which also includes the towns of Bohumín, Havířov, Karviná, Orlová, Petřvald and Rychvald – is home to about 500,000 people, making it the largest urban area in the Czech Republic apart from the capital Prague.