The meaning of the manicure has been transformed in the last few years. Until recently, painted nails were a symbol of classic, grown-up elegance. Traditional shades with timeless names – pillarbox red, or ballet-slipper pink – dominated the market. But the boom in nail art and the trend for eyebrow-raising colours – like steel grey, neon tangerine and moss green – have turned the rules upside down. Nails have never been so high profile in fashion and in popular culture and a new generation of young women are using nail polish to express their individuality, their fashion savvy, creativity and even their humour.

Nail art – the painstaking business of painting and gluing designs and tiny jewels onto nails often lengthened with extensions to create a larger canvas – has its roots in small local salons, but has rapidly become big business and a favourite of female celebrities from the worlds of music, sport and fashion. Last year, the American singer Katy Perry attended the MTV awards with a custom-painted manicure in which the names of each single from her most recent album were represented on different nails. Rihanna has been photographed with hundreds of different eye-catching manicures, from Acid House smiley faces to sharpened metallic talons. Fresh from the manicurist, many Instagram their new looks around the world.

At the 2012 Olympics, patriotic nail art was the trend to sweep the park, with Rebecca Adlington's union flag nails competing for attention with US swimmer Missy Franklin's stars and stripes. The Olympics became a showcase for the wholesome, family-friendly face of nail art – a stark contrast with 2010, when the troubled actress Lindsay Lohan famously painted "fuck U" on the fingernail of her middle finger for a court appearance.

That the nail art phenomenon took off at the Olympics reflects the fact that London has long been the engine room of the trend. The young entrepreneur Sharmadean Reid, a pioneer when she founded WAH nails in Dalston in 2008, has been key in pushing the boundaries of painted nails, as has Vogue-endorsed nail technician Sophy Robson− who has been responsible for some eye-catching magazine manicures.

Beauty bloggers are currently tipping the half-moon manicure – an updated version of the traditional French, in which the half-moon at the base is painted a contrasting colour to the rest of the nail, as the coming trend. Lake Bell, the writer, director and star of hotly tipped new comedy In A World, sported the look in navy and gold at the Sundance Film Festival this year.