The spring/summer 2021 runways were awash with a sunny, daffodil yellow. At Altuzarra, it appeared on business-appropriate blazers and belted midi dresses, while Celine’s Hedi Slimane — once a purveyor of the all-black look — used it on off-duty hoodies and bomber jackets. Dolce & Gabbana offered a one-shouldered dress and matching strappy sandals fit for a Capri cocktail at sunset. (Vacations, remember those?) Gucci, JW Anderson and Dries Van Noten all luxuriated in this happy hue. Were designers simply all feeling optimistic, or is there more to the consensus than coincidence?

“When I was a student, I’d look at the shows every season and I’d always think, ‘Are they told to use this specific colour?’” says London-based designer Rejina Pyo. The answer is, essentially, yes. Runway trends are the result not of coincidence but of colour forecasts. Created up to two years in advance, these reports are sold to fashion, interiors and beauty brands by forecasting agencies such as WGSN and colour firms like Pantone. Pantone’s “Colours of the Year” for 2021, unveiled last December, are “illuminating yellow” and “ultimate grey” — one only has to look at Prada’s womenswear to contemplate the influence.

“That [information] is coming from this nucleus of 20 or 30 people around the world who are seen as colourists,” says textile agent Andrew Moss of this sleuthy team of tastemakers operating behind the scenes, their colour prophecies then infiltrating the wider world.

But “you can’t simply pick a colour arbitrarily and say ‘Here’s the hot colour,’” insists Leatrice Eiseman, executive director of Pantone’s New Jersey-based Color Institute — the forecasting arm of the company best known for its colour-matching system, which is adopted as a design language by manufacturers globally to ensure products and graphics are produced in the correct shade. Eiseman heads up a team of 10 who scour the world for inspiration and insights as to where the colour market might be heading.

“We look at the world of entertainment and what’s in production, especially animated children’s films, as animators are always right on top of new ways of showing colour,” Eiseman says. “We look at food — what’s gaining prominence because of the health movement? We [usually] look at sports events — what colours are most significant within the host country? We think about how people are spending time and what are people looking at — what flowers, what houseplants?” The more people are seeing certain colours across different touchpoints, the more likely it is for a particular shade — such as millennial pink — to go mass.

“It’s an involved process, but we basically track colours bubbling away in certain sectors and amalgamate all the data to predict where the industry is going to be in two years’ time,” says Jenny Clark, head of colour at WGSN. “Colour is one of the most powerful tools to engage customers. We help our brands to make sense of the market.” In 2019, when she was thinking about the 2021 forecast, works by sculptor Brian Rochefort and floral photography by Doan Ly were on her mood board.

Art plays a significant role. “If a painting is doing ‘well’ in the market, it’s a sign that those colours will end up being popular,” says artist Cassi Namoda, who formerly worked in fashion — for a time as a colour forecaster. Today, the Mozambique-born painter is known for her technicolour figurative works. A canvas titled “Maria’s Free Spirit” depicts a woman in a banana-coloured jacket; in January, poet Amanda Gorman wore a Prada coat the exact same hue at President Biden’s inauguration. (Incidentally, a new edition of Gorman’s poetry book, The Hill We Climb, features a yellow coat on the jacket too.) Artist Amoako Boafo catapulted to collectors’ acclaim in 2019, during Art Basel Miami Beach that December; a star-studded dinner was held in his honour. His exhibit at the fair featured mango-hued paintings hung on pineapple-coloured walls. Earlier this year, he collaborated with Dior on a menswear collection — it featured yellow turtleneck sweaters.

Of course, not every designer buys into the reports. But fashion brands are indirectly influenced by them because the textile mills do. “There are about 50 mills in the world that really make a difference in ready-to-wear,” says Moss, who acts as a middle man for over 30 global mills and the UK fashion market. He works with “virtually every British [luxury] brand”, including Pyo, Stella McCartney and Victoria Beckham. When we speak, he’s in the middle of showcasing materials for spring/summer 2022, and says he sees colour trends coming through in the fabric swatches every season — though he remains tight-lipped as to which hues to expect.

For next year and beyond, Namoda anticipates lots of magenta — the colour of compassion, according to the artist — as well as pale greens, browns and lilac baby blues. Brown, she says, is a reverent colour, worn by monks, while the baby blue is a symbol of innocence. Namoda, who says colour today is widely accepted as a visual language, was drawn to those colours when painting works for her forthcoming exhibition, which opens in Brazil in May. “Magenta was uncanny, because we’ve not seen a lot of it in the past few years, even in fashion.”

But when a colour hasn’t been around for a while, it is a sign that forecasters might bring it back. “Fashion is cyclical,” says Eiseman. “If a colour hasn’t been popular, bringing it back in some variation can cause people to look at it because it seems very fresh.”

Namoda, Eiseman and Clark all expect green to feature in coming years — the time spent among nature during the Covid-19 lockdown will have an ongoing impact. But which hue of green to expect? If the art world is anything to go by, then we’ll see a lot of fresh basils and rich, forest pines — a result of Lynette Yiadom-Boakye’s blockbuster exhibition at the Tate, which will, at some point, travel globally. While yellow is said to represent enlightenment, green symbolises growth, new beginnings and health. Here’s hoping.