In the animal kingdom, fluorescent colours come as a warning – take the electric-bright spots on poison dart frogs signalling their toxic exteriors, or the luminescent glow of the blue-ringed octopus that cautions against its deadly bite.

The dazzling hues seen on the spring/summer runways this season are more affable. At Alexander McQueen, Sarah Burton’s cerulean wool suit was inspired by the romanticism of William Blake’s poems and paintings, its stark colouring offset by a classic double-breasted jacket and pleated trousers. And Virgil Abloh’s collection for Louis Vuitton found head-to‑toe lime, fuchsia and electric blue suits merging tradition with early rave culture.

The fluoro suit has historically been regarded as more gesture than fashion statement. As Charlie Porter, author of What Artists Wear, points out, vivid tailoring is often used by designers to “pep up” the catwalk. “They used it to keep editors awake,” he jokes, referring back to Calvin Klein’s collection from spring 2009, where creative director Italo Zucchelli interrupted an otherwise monochrome runway with a series of neon suits. “The purpose of tailoring is for the man to pretty much disappear – it covers all sins. If your whole body is fluorescent, the opposite is happening.” 

Blending in is no longer requisite – nor desirable. According to fashion search engine Tagwalk, colour-blocking in the summer collections was up 273 per cent compared to last year, with many designers opting for luminous alternatives to more traditional shades. “There is novelty in vivid colour,” adds Porter. “It excites the eye and does something to the brain.” 

MatchesFashion’s head of menswear, Damien Paul, says the explosion of daring colour and print this season is “boundary-breaking and uplifting”, as well as a form of self-expression. For maximalists, he recommends neon tailoring by Belgian designer Walter Van Beirendonck – or to go pink and louche with Tom Ford’s offering. “Wear without a shirt and let the suit do the talking,” advises Paul.

For Paul Smith, the colourful suit is simply optimistic. “I am blessed with being a particularly positive person and I think this is often very obvious in my designs,” he says. The designer takes fluorescence back to “the great outdoors” and “the spirit of adventure”; the sunrise oranges and sky blues wouldn’t look out of place in the aposematic animal kingdom. The only difference? There’s no risk of getting hurt.