A veritable army of product developers are eagerly turning nail polish, that once staid cosmetics staple, into a must-have capable of transforming nails into miniaturized canvasses for some of the nerviest experiments that fashion permits.

In recent months, cosmetics makers have invested in lacquers a kind of daring all but unheard of a decade ago, introducing innovations from glitter and crackled surface treatments to stick-on nail art and even scents, and imbuing their products with every color known to nature. And even some that nature would abhor.

Muddied orange, toxic green and shrieking mauve, rare in the marketplace six months ago, are crowding the shelves of department and drugstores, snapped up by consumers intent on releasing their inner Nicki Minaj. Women’s enthusiasm for brazen tints, 3-D effects and quirky patterns (think python, cobweb or cheetah spots) has propelled nail polish into the fastest-growing segment of the beauty trade, surpassing even lipstick as a recession-proof cosmetic enhancer.

“Nails come in any way, shape or form,” said Karen Grant, a senior analyst with the NPD Group, which tracks cosmetics trends. “They’ve become a fashion accessory.”

The advent of brashly adventurous, and sometimes garish, colors and designs coincided roughly with the collapse of the Dow, when consumers came to regard lacquers priced from $10 to as much $30 as a cost-effective way to brighten their turnouts – and outlooks. The eye adjusts, and today the acid tints and swirling patterns that five years ago were outre have entered the mainstream.

The more radical they are, the more desirable, it seems, kinky nails having acquired a cool factor more recently reserved for niche fragrances. So hip are the new lacquers from mass marketers like Essie and Sally Hansen, and from trendsetters like Nars, that pop stars including Katy Perry, Justin Bieber and Avril Lavigne, and even the designers Thakoon Panichgul and Prabal Gurung, have attached their names, and their images, to high-end and drugstore brands.

“We used to talk about the lipstick index,” Renato Semerari, president of Coty Beauty, the parent company of top-selling brands like OPI and Sally Hansen, said, referring to the theory that lipstick sales are inversely correlated to economic health. “Now we talk about the lacquer index.” Semerari ascribed stellar sales mostly to the fact that “these days there is so much more to buy.”

Indeed, there are more colors than in a pack of Skittles, many of which can be applied in one’s bathroom. That DIY appeal has been a plus for mass marketers who, according to consumer research firm Kline & Co., are racing to offer colors and glazes approximating those of the priciest salons. So successful are some shades that they have spawned cults (among them, Particuliere, a mushroom gray-brown from Chanel that in 2010 engendered wait lists and bidding wars on eBay) as well as a raft of copycat shades.

For summer, Chanel will introduce a blackened orange that Peter Philips, creative director for Chanel Makeup, predicted would attract the consumers who embraced the season’s crazy-salad prints. But its appeal, Philips suspects, would not be confined to vanguard types. Unlike tattoos or knee-high gladiator sandals, a nail varnish requires no significant outlay of cash, much less an emotional commitment.

“At one time a woman had a look, and she stuck to her look,” Philips said. Colors like yellow or steely gray represented a risk. But now, he said, when fashion identities have become as fluid and interchangeable as computer wallpaper, “you can be Dita Von Teese one day, and in the same week you can be Lauren Hutton.”

“Nail polish is just makeup,” he added. “If it doesn’t work out, you can wipe it off.”

Even risk-averse women, who would be loath to dye their hair fuchsia or wear a calf-length pencil skirt, may be tempted to experiment on their fingertips. “The farther you travel from your face, the more willing you may be to wear something daring,” said Allure magazine Editor Linda Wells. “People who shun multicolored tequila sunrise eye shadows will paint their toes and fingers green.”