Colour the key to victory on ladies' day - on and off course

Forgive me my Y chromosome, but a dress is just a dress, isn't it? And a hat a hat, for a' that? Well, we learn something every day, and ladies' day at the Cheltenham Festival must be no different. The learning curve rises sharply before me and I step gingerly on to it, holding the handrail for safety.

"It's the perfect day for ladies' day," says Alice Linley, daughter of the more famous Richard, robed in a roseblush peacoat that would certainly put her on the judges' shortlist were it not for the fact that she's running the show. She outlines the protocols of the afternoon in that bewilderingly matter-of-fact way women adopt when discussing high fashion, that leaves men always half a step behind despite having the more sensible shoes.

Today there are two competitions, the marquee event – entries via social media – no doubt judged mercilessly by fashion experts Elizabeth Grant, the reigning Miss England, and Roz Purcell, and a broader contest with five prize-winners carefully selected from those among the throng making their way through the gates in weather borrowed wholesale from mid-June. Emelie Kelman and Antonia Pocknell, one of several pairs of spotters clad in Guy Reed pink and bearing double handfuls of elegant enamel badges to bestow upon the chosen few who will form the long-list, from which winners will be drawn at random, begin the search.

"We've got around 40 minutes to hand out the badges," says Kelman, stressing that the emphasis is on colour used wisely and well, pointing to the slogan #colourmemarch. Black and white may be chic, but it won't win any prizes today. Pocknell wants fuchsia, pillar-box red, turquoise and teal, orange and lemon, and the whole palette streams around us in glorious harlequinade lent a shimmer by the sunshine.

"Am I young enough?" says one woman, a vision in shades of purple. Kelman and Pocknell assure her that elegance knows no boundaries of age, and she takes the badge, adds her details to the database, scans the list of prizes – a car, a diamond necklace, vouchers for fashion houses, tickets to the races. "You've made my day, picking me out like this," she says, and we walk on through the crowds, looking for other days to make.

The men conform to the stereotype of spring in the shires, a tidal wave of tweed shot through with dark suits and brown felt hats, the effect going against nature that gives the cock pheasant all the showy plumage and the poor hen the drably brown feathers. Here, there and everywhere is the frequently derided occurrence of primary-colour corduroy trousers, red, yellow, green, a group of culprits from the waist down resembling a pack of felt-tip pens.

We're looking for colour, but not that sort of colour.

It's not a difficult job, for there are so many candidates but so few badges. Shorn of the whiff of narcissism that accompanies Ladies' Day at Royal Ascot, Cheltenham's version adopts a more egalitarian feel, although it's perfectly clear that precious few of these outfits have been thrown together in a morning. With the clock running down, Kelman and Pocknell pass over a couple of badges and allot spotter's duties to me, the most unlikely Gok Wan imaginable.

"My outfit was three months in the planning," says professional photographer Stefanie Calleja-Gera, whose beautiful blue and white Gucci shoes clinched her a badge. "The outfit was based around the shoes – the dress is Ralph Lauren, my coat is Beatrice von Tresckow, and my hat was made by Lisa von Hallwyl."

Thrown slightly by this profusion of 'vons', I regain a foothold in the conversation when she says she's backed O O Seven in the RSA Chase. Then a man stumbles past wearing open-toed sandals, and the spell is broken with a crash. I offer a badge to Calleja-Gera's companion, who turns out to be the very same Lisa von Hallwyl, wearing one of her own creations, a sumptuous green feathery affair.

"This hat? It took about three months to make," says the milliner, whose showroom in Bishop's Cleeve is the source for several examples of today's most eyecatching headwear. "I love to see my hats at the races, it's so exciting, especially on a day like this."

Colour is the name of the game on ladies' dayCredit: Matt Cardy

There are other excitements in store, notably Might Bite, whose rider Nico de Boinville surely deserved one of our enamel badges for carrying off the difficult combination of blue and yellow check and black and orange hoops with such sangfroid. Apt too, on ladies' day, is the victory of Special Tiara for owner Sally Rowley-Williams (small hat, green feathers, matching bag), the founder of the burgeoning Women in Racing organisation.

There are other prizes still to be won, though, and back at base the focus is firmly on badge 381, whose bearer has won the car. But where is she? Eventually, after a great many nervous looks exchanged between Jockey Club employees, Rebecca Johnson – the fiancee of Nottinghamshire trainer Scott Dixon – strides up in a striking red dress to claim her new motor.

Another lengthy pause precedes the denouement of the Best Dressed Lady competition, our contenders choosing the right moment to slip through a gap between Fred Winter runners and into the parade ring where the champagne and flowers await. The announcement, made in 3-2-1 reverse order, has little in the way of suspense given that there are but three finalists, so once Gillian (green) has been called third and Jen (pink) second, the overall winner is inevitably Una O'Farrell-Feeney (blue) from Coalisland in County Tyrone.

"This is totally unexpected, I'm totally overwhelmed," she says. "I don't go racing very often, I'm a novice really. I started thinking about what I'd wear about four weeks ago, so it was quite a quick turnaround.

"The dress – it's teal, I'd say, or maybe a petrol blue – is by Malene Birger, who's a Danish designer. The shoes are Reiss, and I've just had the gloves in the wardrobe for some time, waiting for the right time."

Few assaults on the back of the wardrobe can have resulted in such success. The bottles of champagne are handed around decorously, no Formula 1-type spraying in these circumstances, not with all that finery at risk. O'Farrell-Feeney wears a smile as wide as any Cheltenham winner; not just a dress, not just a hat, not at all.