Green’s Dictionary of Slang

blue adj.3

also azure, indigo
[? bluegown under blue adj.1 , the Fr. Bibliothèque bleue, ‘a series of books of questionable character’ (F&H) or as the opposite of brown adj.2 (1); note the papier bleu which in 18C covered the pornographic or seditious material on the tray of a colporteur, an itinerant Parisian bookseller]

coarse, obscene, pornographic; thus blue film, blue movie; thus, constr. with the, coarseness, obscenity.

[UK]‘A. Burton’ Adventures of Johnny Newcome I 31: Blush, Pluto! Blush as brimstone blue! This bluer Town can boast like you A ‘facilis descensus’ too.
[UK]J. MacTaggart Gallovidian Encyc. n.p.: Thread o’Blue, any little smutty touch in song-singing, chatting, or piece of writing.
[UK]Sam Sly 5 May 3/3: We advise certain young ladies not to be so fond of listening to the ‘blue’ talk of the long carrier, of King-street.
[UK]Hotten Sl. Dict.
[UK] ‘’Arry at the Play’ in Punch 2 Nov. in P. Marks (2006) 40: Sly sarce [...] with a dash of the blue, but mixed weak.
[UK] ‘’Arry on Song and Sentiment’ in Punch 14 Nov. 229/1: To cut a fair dash, dress slap-uppish, ’ave fourpenny smokes and good drink, / With a touch of the azure for fun, and for yum-yum a patch of the pink.
[Aus]Dead Bird (Sydney) 30 Nov. 2/1: Some books are not fit to burn, far less to read. Blue books?
[UK] ‘’Arry on the ’Oliday Season’ in Punch 16 Aug. 75/1: Chic, spice, azure pictures, rum crimes, / Is all very good biz in their way.
[UK]Sporting Times 25 Jan. 1/1: Shifter wondered whether the damsel knew any novel blue stories.
[Aus]Truth (Sydney) 19 Feb. 1/4: The smart burlesque they call ‘Don Juan’, / Comparatively it’s a new ’un— / Is interdicted as a blue’un / Because it shows how harems do ’un.
[US]Ade Artie (1963) 91: You ought o’ heard some o’ the large blue language the old man got rid of.
[Aus]Bulletin (Sydney) 20 Oct. 12/4: Let someone propose to celebrate Chaucer by publicly reading some of his bluest productions unexpurgated. The reader would probably be locked up by the police, but there would be more real Chaucer in the thing than in the spoutings of the professional fuzzy-wuzzies.
[UK]J. Conrad Lord Jim 122: So I turned to him and slanged him till all was blue.
[UK]E.W. Rogers [perf. Marie Lloyd] The Red and The White and The Blue [lyrics] Let them keep the blue, the’'re blue enough, French papers so obscene, / But let them keep their hands of English women’s lives so clean.
[[Aus]W.A. Sun. Times (Perth) 30 June 1/1: This reputedy bashful person was co-respondent in a particularly cerulean Eastern divorce case].
[Aus]Bulletin (Sydney) 7 Sept. 32/1: High-kickers are not in the least concerned / By the leers of the Bald-heads ‘blue,’ / But little they dream of their charms up-turned / To the gallery’s bird’s-eye view.
[UK]Sporting Times 20 May 1/4: The judge indignantly interdicted the reading aloud of any more blue passages.
[UK]‘Doss Chiderdoss’ ‘The Censor’ Sporting Times 29 Aug. 1/3: He told him some stray legends of a hue which would outvie / The deep azure of the firmament in sun-embraced July; / [...] With some excerpts from sundry playlets of so indigo a dye / That they’d one and all been outed by the censor.
[Aus]Bulletin (Sydney) 8 Aug. 16/4: There was a time – so pundits say – / When language of the purest blue / Arose and wreathed in bright array / The finest thoughts of that purlieu; [...] / But Billingsgate has grown polite.
[US]‘Hugh McHugh’ You Should Worry cap. 9: I had sneezed myself into a condition of pale blue profanity.
[US] (ref. to late 19C) N. Kimball Amer. Madam (1981) 325: I still kept out voodoo and the faggot and lesbian acts and the blue movie stuff.
[US]W. Winchell On Broadway 21 May [synd. col.] The girl, a spirited person herself, made up the pauses in conversation with some deep indigo phrases of her own.
[US]W. Winchell On Broadway 30 Oct. [synd. col.] The same booklet [...] illustrates on page 122, the blue nifty that made your correspondent a sophisticate at P.S. 184 back in 1910.
[UK]V. Davis Phenomena in Crime 34: The bluest profanity always ‘on tap’.
[US]Green & Laurie Show Biz from Vaude to Video 46: Vaudeville belonged to the pie-throwers and comics who fished for laughs with slightly ‘blue,’ or suggestive material.
[UK]‘Charles Raven’ Und. Nights 152: Touting for an outfit that supplied blue film shows to tired business men.
[US]W. Burroughs Naked Lunch (1968) 109: That international-known impressario of blue movies and short-wave TV.
[UK]G. Lambert Inside Daisy Clover (1966) 63: People were drinking away and getting to the blue-joke stage.
[UK]N. Cohn Awopbop. (1970) 191: She gave interviews saying that blue films should be legal.
[US]T. Southern Blue Movie (1974) 14: ‘Soirée cinématique!’ she screeched, ‘Soirée du film blue!’.
[UK]Manchester Guardian Weekly 2 Aug. 20: Bette Midler is [...] no Streisand, her material is blue and her songs are old. Yet she’s been camped out at one of Broadway’s biggest theatres for several months now, making raunch respectable in a sellout revue called Clams on the Half Shell.
[NZ]H. Beaton Outside In Act II: sandy: Blue movies? ginny: Yeah. Had a film on VD. Fascinatin’! Put you off eatin’ sausage, Kate!
[US]R. Campbell Alice in La-La Land (1999) 105: Jokes that just missed turning blue.
[UK]A. Frewin London Blues 9: You’re quietly going about shooting blue films with attic camera set-ups.
[UK]G. Burn Happy Like Murderers 341: The house was full of blue magazines and blue movies. Dirty books and dirty films.
[UK]J.J. Connolly Layer Cake 76: For the time being I better just switch off the blue movie in my nut.
[Aus]M.B. ‘Chopper’ Read Chopper 4 235: My dirty ditties and short stories are somewhat bluer that [sic] anything the gentle Banjo ever told.
[SA]M. Orford Like Clockwork 136: Some of our customers like to star in their own blue movies.

In compounds

blue light (n.)

see separate entry.

In phrases

burn it blue (v.)

to act outrageously, poss. by speaking very coarsely.

[UK]Swift ‘Strephon and Chloe’ in Medley (1749) 110: Miss Moll the jade will burn it blue.
make the air blue (v.) (also make the air turn blue, turn the air blue)

to swear, to use obscenities.

[UK]Oracle XII 28: And nightly I painted, Vermillion, the town; / Or with flashes of crimson, I varied the hue, / While language Soph’moric, Would make the air blue.
[US]Frank Leslie’s Popular Monthly XXIII 278: [...] curses enough to make the air blue.
[UK]Farmer & Henley Sl. and Its Analogues I 256/1: To make the air blue, phr. (popular). — To curse; to swear; to use profane language.
[US]J.A. Mitchell Life 491: Some rhymed with ‘ham’ / And ‘Sam’ and ‘flam,’ / And some with ‘revel,’ too; / And some with ‘well’ / And ‘William Tell,’ / That made the air turn blue.
[US]Bridgemens’ Mag. (US) VII 211: And the language we hear would make the air blue.
[US]O.O. McIntyre New York Day by Day 13 June [synd. col.] The prim buttoned-up life of the upper avenue [...] was treated to a midafternoon verbal skirmish that fairly turned the air blue.
[US]C.S. Montanye ‘Don’t Meddle with Murder’ in Thrilling Detective May [Internet] Barney pushed his leather-swinger into a bathrobe [...] leaving the air blue behind him.
[NZ]F.A. Cleary A Pocketful of Years 67: He’s cursing and swearing till the air is blue.
[Aus]R.G. Barrett You Wouldn’t Be Dead for Quids (1989) 30: ‘You rotten, fuckin’ thieving cunts,’ he screamed [...] The air was starting to turn blue now.
[Aus]D. Finkelstein Greater Nowhere 115: But their language on return to town made the air turn blue, / The stupid Yankee so-and-so had run over a kangaroo.