If the oversized spokes-candies in front of the building don't get the point across -- Red and Yellow hold up the awning while Miss Green and Ms. Brown sit cross-legged on top -- the smell hammers it home. Imagine a saccharine whiff of candy apples fused with the rich essence of a fudge factory. It is everywhere and it is inescapable.

Here in Hackettstown, at the northwestern edge of the state in a sprawling complex on High Street, Mars Incorporated has been churning out M&M's, the company's iconic candy-coated chocolates, since 1958. Yet the candy-maker has called New Jersey home even longer -- 2015 marks 75 years.

Mars may have deep roots in the state, but the company's approach to selling M&M's has changed much over the last decade. The public perception of sugary products has resulted in some significant about-faces in the marketing of the chocolate buttons, which debuted in 1941 and were at first supplied exclusively to the military because of their resistance to heat ("Melts in your mouth, not in your hand").

Today millions of M&M's -- nearly half of the total sold in the United States -- are produced in Hackettstown every year. The Mars campus is spread out over 104 acres, at a site that used to be inhabited by a farm. The plant alone measures 460,000 square feet, but the compound also serves as the headquarters of Mars Chocolate North America, which manages a sea of candy brands, from Dove bars to Twix.

The Blue Mile

A walk through the M&M's plant -- usually, only new hires and family members get the privilege -- isn't exactly the stuff of Willy Wonka wonderland. While there are vats of swirling, shiny chocolate, there are no musical numbers or children with golden tickets dancing in their eyes. There is IP -- intellectual property -- company practices and procedures that Mars doesn't allow to be photographed or recorded. A sign on the lobby desk informs visitors about confidentiality expectations -- that they will not "disclose such information to any third parties."

The 'Blue Mile' hallway of the M&M's plant in Hackettstown. (Amy Kuperinsky | NJ Advance Media for NJ.com)

Inside the plant, employees refer to a long sterile hallway as The Blue Mile for the color of the floor. The M&M's-making process starts in a segment of the factory that clocks in at a not-so-tolerable 96 degrees Fahrenheit. Andy Burns, shift lead, will grab a few finished M&M's from time to time.

"With all things moderation," he says. He'll just sweat off the calories, anyway.

What starts as a chocolate paste moves to a conching stage in which chocolate is mixed with cocoa butter and smoothed before heading to a tempering unit to ensure optimal "shine and snap." The company used the same hefty conching machines in 1941. There are more than a few such souvenirs from Mars' original location in Newark -- the company last occupied a factory there at 200 North 12th St.

"A lot of these pans are older than I am," says Jim Price, 50, quality and food safety manager, gesturing to pods in which the M&M's tumble around for five to seven hours of continuous color spraying. Price is one of 1,000 "associates" who work in the Hackettstown plant.

Mars Chocolate brands

M&M's are made in Hackettstown as well as Cleveland, Tennessee and Topeka, Kansas. The millions of M&M's made in Hackettstown account for almost half of the total sold in the United States.

After going through a polishing tube, the candies head for what Price calls a "very secret" printing process that is not part of the tour, the stage where the white "Ms" are applied to the candy. Joking about the exclusivity, he is quick to dispel any rumor that hand-painting is involved -- or Oompa Loompas.

"I haven't seen it," says Anthony Guerrieri, 33, spokesman for Mars Chocolate North America.

In the packing room, Jackie Bailie, a Mars "team member" who grew up in Hackettstown with the factory smell wafting over her home, ensures M&M's bags are sealed properly. She opens one every hour to check for quality. However the bite-sized candies are not her favorite Mars candy -- that honor goes to Snickers.

The Martians

Even though there's not all that much whimsy on supply in the M&M's plant, more fanciful evidence that this is a candy company can be found in the adjacent headquarters of Mars Chocolate North America. Employees call themselves Martians. The vending machines dispense free M&M's, Snickers, Twix and Milky Way bars.

Signage for a quiet nook inside the Mars offices. (Amy Kuperinsky | NJ Advance Media for NJ.com)

On the flip side, employees have access to treadmill desks and a gym. Though there are technically no offices -- the workspace is open-plan -- rooms are named for brands and characters.

A conference room is modeled after a Snickers bar, with a brown ceiling for the chocolate and irregular-shaped drop lighting for the nuts.

Still, the sweet aroma of M&M's isn't always pleasant, especially when it becomes your personal smell. In the attempt to divorce themselves of the special essence of M&M's, some employees keep their street clothes in a sealed plastic bag so they can change after work. When stale, the sugary scent can conjure the distinct odor of "baby puke," says Sarah Wagner, 30, senior assistant brand manager.

Jeff Herb, 59, a facilities and services manager, has worked at Mars since 1975. If people ask about the smell in his car, he always has a reply -- "That's my paycheck."

Mars claims a total of 1,500 employees in New Jersey. Others work at the global chocolate headquarters in Mount Olive and Mars Retail Group in Mount Arlington.

Jackie Bailie, a Hackettstown local and M&M's employee (Mars calls her a 'team member'), checks bags of candy for imperfections. (Amy Kuperinsky | NJ Advance Media for NJ.com)

The candy company runs in three generations of Nicole Lee's family. Her grandparents were employees of the Newark plant. She started out in the packing room during summers off from college. Now 32, she's an internal communications manager.

"It's just kind of a part of who you are," Lee says. "I grew up with it."

'Not a food'

Mars has grown exponentially since 1911, when Frank Mars started selling candies out of his home in Tacoma, Washington. Today based in McLean, Va., the private company says annual net sales amount to upwards of $33 billion. More than 100 years later, there are other changes. Marketing strategies have been altered to address consumer concerns about calorie counts and sugar.

"We don't advertise to children 12 and under," says Tracey Massey, president of Mars Chocolate North America. In 2013, the company rolled out front-of-package labeling of calories-per-serving on all products (plain M&M's have 240).

Massey, who assumed the post last year, hails from England, but has lived in the U.S. for 11 years and worked at Mars for 25. One constant of the job is having to formulate a response to the notion that there are various flavors involved in M&M's.

"They'll say, 'Oh, I like the blue ones!'" she says. Another refrain: "How are you not the size of a house?"

"Chocolate is an indulgence," Massey says. "It's a treat. It's not a food."

In January, M&M's Crispy (180 calories), introduced in 1999 and discontinued in 2005, were brought back after customers kept asking about the candies with the crunchy center. For her crunch, Massey prefers M&M's Pretzel.

Tracey Massey, president of Mars Chocolate North America. (Mars)

Her reasoning: At 150 calories per serving, she can afford to eat more of them.

Mars' Dove Chocolate Discoveries program, launched in 2007, banks on the persistence of "treat" mentality in adults. "Be a chocolatier -- no experience needed," trumpets a pitch for women to -- a la Tupperware -- host chocolate parties, selling items like chocolate martini mix.

One wall in the plant tracks the evolution of the M&M's spokes-characters from peppy-faced rounds taking candy showers and diving into milk-chocolate swimming pools to more human-looking candy people. Massey says the company does not use children in its advertising. The current aim: "adult humor" -- adult humor she calls "a bit silly."

In 2014, a Super Bowl commercial teaser saw Yellow, the peanut M&M, twerking. A current TV spot uses an action-film feel to advertise M&M's as movie candy.

"We're all gonna die!" screams the character Orange, frantically driving a bus. The band of spokes-candies are seen strapped to a missile, a timer ticking away for blastoff.

"This is the movie you've all been waiting for," a narrator says. " ... That's actually not a movie. But really, just a commercial ... reminding people to eat M&M's."

Amy Kuperinsky may be reached at akuperinsky@njadvancemedia.com. Follow her on Twitter @AmyKup. Find NJ.com Entertainment on Facebook.