Hannibal wouldn't work without a small detail in real life
The show would not have been the same without Hannibal's three-piece suit and iridescent tie, or Will's plaid shirt and rumpled jacket.

NBC's series Hannibal stands out for the way it uses visual world-building to highlight the story. Many viewers may not have noticed these subtle details, but they elevate the show by adding extra nuance and care to the series as a whole. Showrunner Brian Fuller draws on Thomas Harris' gothic psychological novels more than the famous films "The Silence of the Lambs," "The Red Dragon" and "Hannibal." The result is surreal horror with a multi-sensory, stylized aesthetic.
Hannibal Lecter's character is brutal, a cannibalistic murderer, but he exudes elegance. This is reflected in the interior design of his home and office, his demeanor, his personal style and of course his cooking. The cannibal Hannibal is a psychiatrist, but he lacks empathy completely. This is in stark contrast to Will Graham, whose strong empathy and vivid imagination made him an effective investigator, but also damaged his sanity and made him Hannibal's prime victim .
Hannibal Needed Its Incredible Costume Detail

Hannibal's most visually distinctive feature is the costume. The choices were deliberate, and Hannibal costume designer Christopher Haggerton used costumes to convey deep character traits and plot shifts. Small details are prevalent in the series, such as Franklin Froideveaux, Hannibal's patient, imitates Hannibal's attire to show his growing obsession with Hannibal. Frederick Chilton, director general of the Baltimore State Mental Hospital where Will was incarcerated for a time, did the same while gradually imitating Hannibal, but Chilton's bold ill-fitting tartan didn't fit. His poor taste stands in stark contrast to Hannibal Lecter's impeccable taste.
Most TV shows dress their characters in costumes by simply choosing something that looks good, without bothering to use costumes to enhance the show's storytelling. Hannibal could have been done with regular suits and "police uniforms," like any of a hundred procedural crime dramas, but it would have lost a key component: the visual impact of the character's wardrobe. Hannibal Lector in a cheap suit wouldn't be nearly as scary. It's his sharp, restrained and methodical exterior that complements his methodical yet artistic nature, and together they make for a deeply disturbing villain.
How Hannibal's Costumes Reveal Character And Plot Details

Each character in Hannibal has a "appearance" that clearly identifies them. The look changes subtly to account for the mood or environment the character is in. Early Will Grahams wore mostly earthy tones, although utilitarian and utilitarian As the story progresses, he begins to trade his fly-fishing vest and rumpled jacket for tailored wool coats and sweaters, just as Hannibal is increasingly drawn to it. Will's gruff, off-handed appearance in his early years reflected his battles and his inner demons. He is terrified and loathed by the darkness within himself. As he began to accept and embrace this darkness and Hannibal, his clothes became more fitted and more polished.
Hannibal Lecter's wardrobe is dominated by patterned three-piece suits, sophisticated ties, square scarves, textured shirts, and slim-fit trousers. What he dresses is another way he controls his narrative and how people perceive him. His own psychiatrist, Bedelia du Maurier, called Hannibal's attire his "people's suit." He'll change this on purpose to fit, like when he visits the FBI in the first episode of season one wearing a beige suit and sweater.
Women in Hannibal are no exception. Alana Bloom, Hannibal's former student, is sleek and confident, but she too has begun to dress in the style of Hannibal's suits. She transitioned from feminine wrap dresses to sharp blazers. Freddie Lounds, a grim reporter in all sorts of prints, Mostly those dangerous predators. In one scene, she shows up in Hannibal's office wearing a jacket that looks like marbled meat. This is "Armor" by Freddie Lounds.
In Gavia Baker-Whitelaw's Behind the Seams episode Dressed to Kill: The Costume Design of NBC's Hannibal, she decodes Hannibal's costume choices and explains how they greatly accentuate the storyline. Hannibal's dark opera needs a little color, and each carefully chosen costume provides that while revealing subtle details of the characters and plot.