For some, fashion means a wardrobe makeover for spring. Then there are those for whom it means an elaborate neck tattoo.
The same holds true when it comes to iPhones. Most people are happy to personalize their phones with, say, a case covered in plastic jewels. But some opt for surgical modifications.
Apple, of course, has decreed that iPhone buyers can choose any color they want, as long as it is black or white. That has prompted some rebels to transform their devices by, for example, replacing the front and back panels with colorful and unauthorized alternatives, ensuring that they stand out amid a sea of millions of identical phones.
“Apple wants the phone to be a black box, and replacing the back is like saying ‘I have control over my device,’ ” said Kyle Wiens, who runs iFixit, a Web site dedicated to hardware repairs and modifications. The site sells a replacement back panel for the iPhone that is see-through, showing off the phone’s innards.
Kelly Dwyer, 40, a musician in Brooklyn known as Killy, was tired of her boring monochromatic iPhone. So when a friend told her about a small but popular shop in the city called DrBrendan that would swap out her phone’s black glass casing for any color in the rainbow, she leapt at the chance.
Ms. Dwyer paid $ 150 to have a candy apple red front and a honeybee yellow back installed. “I want everything to be eccentric,” she said.
Messing around with the iPhone can be expensive and is not without risk — Apple does not condone it and may refuse to service or repair a phone if it has clearly been tampered with. But those who do so say the trouble is worth it.
“It gets a lot of attention,” said Jarrett Pumphrey, 33, who is the chief executive of a maker of orthodontia products.
He replaced the back cover of his iPhone with a custom-engraved, polished piece of walnut. “It’s so different from what everyone else is used to seeing. People don’t know what to think.”
Mr. Pumphrey, who lives in Houston, ordered a kit online from a company called Materi-al6 and did the swap himself.
Ms. Dwyer and Mr. Pumphrey’s modifications are just the start. iPhone owners can choose from a wide palette of new covers and backs, including mirrors, shiny gold and rich, natural woods.
A company called Colorware will even coat the back of an iPhone 4S with glossy or matte paint. There’s even a modification — or mod in tech lingo — that causes the Apple logo on the back to light up with a soft glow to signify an incoming call.
Yuriy Gutkin, 21, runs a shop in Brooklyn called Zeetron that does the color swaps and sells kits for people to do them at home. He said this accounts for up to 20 to 30 percent of his overall business, with much of the rest coming from repairs of broken screens.
Much of the modding culture was born from those fixes. Mr. Gutkin said that accidentally smashing the screen of his brand new iPhone a few years back prompted him to “start looking at what can be done in terms of personalizing it and making it your own.”
Matt Turner, 37, one of the founders of Material6, a small shop in Tucker, Ga., had a similar revelation after his phone fell off a table. Mr. Turner, who was making iPod docks at the time, sanded a piece of wood to the proper thickness, wrestled the glass off the back of the phone and installed his prototype. Then he posted a picture of it on Facebook.
“Everyone wanted one,” he said. “So we decided it was something we could make and sell to the public.”
Now the company sells kits, starting at $ 89, that let D.I.Y. adherents choose from a dozen different hand-carved wooden backs. Mr. Turner said the company received orders for around 10 kits a day, and has plans to expand the line further.
When it comes to hacking the iPhone, most of the focus has been on jiggering its software so unauthorized applications can run on it. But unlike previous versions of the phone, the 4 and 4S are sandwiched with rounded pieces of glass that are fairly easy to remove and replace, making them a hardware hacker’s dream.
For iPhone modders, part of the appeal is in bucking Apple’s strict uniformity. Although it was big news when Apple deigned to release a white phone last April, it has released iPods in a wide variety of shades.
“They had to expand that product line rapidly to compete with other low-cost companies sticking an MP3 player into everything,” said Adam Richardson, creative director at Frog Design, which once worked with Apple.
It’s likely that Apple does not feel similar pressures with the iPhone, said Mr. Richardson, and the tinkerers are not going to change that.
“It’s hard to say they’re missing out on an opportunity here because they have 50 percent of the market,” he said. An Apple representative declined to comment.
It is precisely the iPhone’s reliable conformity that allows related cottage industries to emerge and flourish, said Brett R. Gordon, an associate professor of business at Columbia. Although Apple doesn’t condone modifications, it is providing a kind of hardware platform for people to build on, creating a vast potential market for things ranging from color swap kits to camera-lens attachments.
“Apple is focused on what it is good at, which is designing phones and leaving the third-party world of accessories up to everyone else,” Mr. Gordon said.
The predictability and popularity of the iPhone helps to explain why modding is much less common among owners of other phones. There are dozens of different Android phones on the market, for example, making it difficult for technicians to become an expert in tweaking each one. (The iPad is not a common target for modifications since its glass screen is secured to the case with adhesive, making it more vulnerable to mishandling.)
The next version of the iPhone is expected to veer away from the square shape of the 4 and 4S, which could make it harder to modify. But technicians say they are ready.
“We’re expecting it to be different and we’ll just come up with different products,” said Mr. Wiens of iFixit. “It’s part of the fun.”