Green’s Dictionary of Slang

(orig. Aus.) the act of vomiting.

1963–74		B. Humphries Barry McKenzie [comic strip] in Complete Barry McKenzie (1988) 21: When I’d swallowed the last prawn / I had a technicolour yawn / And I chundered in the old Pacific Sea.
1966		T. Keyes All Night Stand 58: ‘Been sick,’ he said. Honest man. ‘Technicolor yawn,’ I said.
1967		F.J. Hardy in Great Aus. Lover Stories 63: Listen, mate, that’s no spit, that’s the greatest technicolour yodel in history.
1985		B. Humphries Traveller’s Tool 79: Every time a business colleague nicked off in mid T-bone through the swing door for a quick slash or a technicolour yawn.
1992		R.G. Barrett White Shoes 86: Have you ever heard of the expression ‘Having an up and under’? [...] A technicolor yawn? Having a laugh at the footpath?
1993		J. Mowry Six Out Seven (1994) 133: C’mon, bro, let’s us go do the livin-color yawn.
1998		V. McDarmid Star Struck (1999) 137: I hoped it was a chuckle and not the overture to a technicolour yawn.
2000		Indep. Weekend Rev. 12 Aug. 4: When seeing that many ‘Britneys’ off / You get a technicolor cough.
2014		Vancouver Sun (BC) 18 Mar. 8/6: The vomit projectiles sailing through the air that the kids call ‘technicolour yaws’ [sic].
2016		N. Cummins Adventures of the Honey Badger [ebook] VITAL AUSSIE VERNACULAR Vomit: 1. Up and under 2. Chunder 3. The technicolour yawn 4. Barking at the lawn 5. Driving the porcelain bus.