A blue film or blue picture is a slang term for pornographic films in India, usually softcore pornography. The name BLUE is predominantly used for such movies because of the color of the sets involved in filming the scenes, mainly with a motive to conceal the identity of the actors, to ensure safeguard from social stigma, generally attached with such movies.

The arrival of porn star Sunny Leone in the Bigg Boss house in 2011 created a stir in India over the issue of tolerance towards such artists. While the blue film industry is worth a billion, public opinion about porn stars is widely negative. They are considered more of sex workers than actors.

Blue film may also refer to the 2009 Bollywood movie Blue, starring Akshay Kumar, Zayed Khan, Sanjay Dutt and Lara Dutta. At the time it was the most expensive Bollywood film ever produced.

Blue is a colour, the perception of which is evoked by light having a spectrum dominated by energy with a wavelength of roughly 450–490 nm. It is considered one of the additive primary colours. On the HSV Colour Wheel, the complement of blue is yellow; that is, a colour corresponding to an equal mixture of red and green light. On a colour wheel based on traditional colour theory (RYB) where blue was considered a primary colour, its complementary colour is considered to be orange (based on the Munsell colour wheel).

In Modern English, "blue" is one of the basic colour terms, and one of the seven spectral colours, intermediate between violet (purple) and cyan. It comprises a considerable number of identifiable subcategories that can be identified with descriptive terms like navy blue (a dark blue), cyan blue (or "blue-green", on the boundary to the green range), or sky blue (azure).

The word itself was loaned into Middle English from the Old French word bleu, blo "pale, pallid, discoloured; blue, blue-grey", itself from an Old Frankish *blao.

A film, also called a movie or motion picture, is a series of still or moving images. It is produced by recording photographic images with cameras, or by creating images using animation techniques or visual effects. The process of filmmaking has developed into an art form and industry.

Films are cultural artifacts created by specific cultures, which reflect those cultures, and, in turn, affect them. Film is considered to be an important art form, a source of popular entertainment and a powerful method for educating – or indoctrinating – citizens. The visual elements of cinema give motion pictures a universal power of communication. Some films have become popular worldwide attractions by using dubbing or subtitles that translate the dialogue into the language of the viewer.

Films are made up of a series of individual images called frames. When these images are shown rapidly in succession, a viewer has the illusion that motion is occurring. The viewer cannot see the flickering between frames due to an effect known as persistence of vision, whereby the eye retains a visual image for a fraction of a second after the source has been removed. Viewers perceive motion due to a psychological effect called beta movement.