This trope goes back millennia, to the times when only rich people could afford 'clean' white bread, something which was still happening only last century, and the lower classes had to suffice with the bog standard 'dirty' brown bread.
Throughout history, the 'richer' people were more likely to wear white clothes as they could have them cleaned more frequently, had more of them to wear, and did not partake in tasks which were more likely to dirty them, the 'poorer' wearing predominantly darker clothing as these items do not show stains as much and retain heat.
More modernly, sleek and white homes (especially kitchens) and workplace lobbies or laboratories are very expensive to keep aseptically or professionally clean and also, because of the jobs they are required for, associated with financial and career success. Stereotypically it is also shown that rich and 'preppy' children are outfitted in tennis or cricket whites and polo shirts, even when not in the vicinity of the sport, so potentially parents are showcasing their wealth through their children and how pristine they can keep easily-grass stained clothes.
In reality this is almost a Forgotten Trope, with white objects commonplace so no longer solely a form of Conspicuous Consumption, but they were so in the past. Fiction doesn't seem to have caught up yet, or - as per the nature of tropes - still finds it convenient to use white stuff as a signifier of wealth.
This often overlaps with Simple, yet Opulent, in that many things aren't blinged up or pimped out, but being white still makes them opulent.
Has nothing to do with The Cartel and the white stuff they have.
- In a mobile phone advert, there is a man dressed completely in white; sunglasses, cycle - everything - and the advert continues on to how the phone is available in white, but this version costs more.
- The location of some De Beers diamonds commercials is a seaside mansion that's mostly white. Justified, since the couple shilling the diamond jewellery is rarely shown: it's their shadows that are seen, necessitating a contrasting backdrop.
- In Code Geass, the protagonist Lelouch spends most of the story as the leader of La Résistance, decked out in the darkest of dark outfits and motifs—fitting for an organization called the Black Knights. When he becomes the Emperor of Britannia, though, he switches out the dark costumes in favor of a white-and-gold outfit.
- Kaiba Seto in Yu-Gi-Oh! is made of this: white suits, white Badass Longcoats, white dragons, white jets based on dragons, white blimps, white mansion...
- Sesshoumaru in Inuyasha has white hair, white clothing, a white sword... and his mother takes it a step further by living in a castle made of (white, naturally) clouds. Neither is literally wealthy (youkai like them have no use for money), but they are extremely aristocratic.
- In Speed Grapher, Suitengu is currently on the way to collecting all of the money in Japan, and only ever seems to dress in white suits or Badass Longcoats.
- Satsuki Kiryuin in Kill la Kill has a Kamui called Junketsu, which is so white it's referred to as a wedding dress. She is also the heiress of the REVOVS Mega-Corp, and her mother Ragyo (the current CEO) also wears a white and silver dress. The white Kamui contrasts with Senketsu, who is the Kamui of the apparently poor Ryuko Matoi and is colored a blueish-black.
- The Twilight Saga
- The Cullens are shocking white vampires, in contrast to everyone but most startlingly to the Quileutes, who are dark tan with black hair. The Quileutes are obviously natives, and at one point Edward Cullen is referred to as "the freaky pale skinned boy". This may also play on the expectations of immortal vampires being wealthy and native peoples not.
- The Twilight film Breaking Dawn pt. II has the Cullen vampire family, who are obscenely wealthy thanks to their sire Carlisle being a talented doctor and (apparently) good with money. At one point in the movie they casually gift newlywed vampires Edward and Bella with a fully furnished, decorated and wardrobed cottage. Where this trope comes in? The baby room is pure white. While lovely to look at, anyone who is remotely familiar with a baby's tendency to make messes would instinctively cringe at the "gift." There may be some Fridge Brilliance in there when you consider that the Cullens would have been massively ignorant of childrearing so it may not have seemed impractical. Then again, maybe they consider the added workload of keeping the baby room pristine a worthwhile way to kill time?
- In Tom Cruise's Oblivion everything. Everything. Is white.
- Most everything is white on the titular space station in Elysium. Even the people... No, especially the people.
- Sal from Do the Right Thing has a white car, and the most luxury car of the time, to demonstrate how rich he aspires to be - but certainly how rich he is compared to the other people of the neighbourhood, as he actually runs his own restaurant. It is also one of the many sources that separates him from the others in Bed-Stuy.
- American Psycho: Patrick Bateman's luxurious condo is entirely white, establishing him as wealthy but creepy at the same time.
- In Cinderella (1965), Prince Christopher is the only dancer at the ball wearing white... until Cinderella shows up in her magically conjured gown.
- A Connecticut Yankee in King Arthur's Court makes mention of well-to-do eating white bread a few times - "true wheaten bread," as opposed to black bread made with horse-feed, which the huddled masses make do with, if they can even get that.
- The Raiths from The Dresden Files own a lot of white high-price cars and clothing. Played with in that it looks like this trope in action to vanilla-mortals, but is actually the Raiths' way of flaunting their status as the ruling family in the White Court of vampires.
- Lucius Malfoy owns albino peacocks in Harry Potter.
- In the Earth's Children series Ayla's second adoptive mother makes her a pure white outfit for her wedding. When she finally wears it the people watching are impressed. She's marrying a man whose family has much status in their group (the non-monetary version of wealth) but they don't know her so they aren't sure if she's worthy. But when they see her white dress they know that anyone who can have something like that is also of high status.
- Ayla's outfit is amber/dark yellow (the text states it matches her hair), not white. But this trope is still in play with the outfit she makes for her husband, pure white in a method learned from one of the people in her second adoptive tribe.
- In the backstory of The Belgariad, Vo Wacune, the wealthiest city in Arendia, was made of white marble, whereas its rivals Vo Mimbre and Vo Astur were yellow and grey, respectively.
- In The Goblin Emperor, the emperor traditionally wears white, to the extent that new emperor Maia soon anticipates he's going to get fed up with it. Also applies to the set of white lace hangings he receives for his birthday: obscenely expensive, produced by cruel labour practices (workers go blind making the stuff) and offensive because the giver deliberately spent far more money than appropriate on a gift the emperor didn't even want. While also plotting to assassinate him.
- The antagonist of the third Artemis Fowl book was a Corrupt Corporate Executive whose clothes and home furnishings were all completely white.
- In Mistborn: The Original Trilogy, the Final Empire suffered from frequent falls of volcanic ash, staining everything. White homes and white clothes meant that a noble had enough slaves to keep everything clean.
- Chloe King from Unforgiven by Lauren Kate lives in a big McMansion, surrounded by a moat with koi and inside filled with marble and almost exclusively white furniture.
- 2 Broke Girls
- Max Black has dark hair while rich-girl counterpart Caroline is a platinum blonde. Max can also often be seen, when the two are out of their work clothes, in black outfits while Caroline is dressed all in white.
- When they're dressed as cupcakes Caroline is vanilla and Max chocolate.
- In Breaking Bad, the more rich (and evil) the Villain Protagonist and his wife become, the whiter their wardrobe gets. His long-time 'rivals' Gretchen and Elliott, who are millionaires, are shown in the final episode to live in a very white household. Oh, and did we mention that the Villain Protagonist's name was Walter White?
- In the promotional images for Revenge the only person not dressed in white is Jack, the only character considered to be of the working class.
- On Friends when Joey lands a high paying gig on Days of Our Lives he buys a bunch of pointless expensive knickknacks, and when he loses the job it all gets repossessed. Ross offers to buy him one of his purchases back, and he picks a white dog statue.
- In the fifth season of Mad Men, Don and Megan Draper are shown to have a white carpet in their luxury penthouse apartment, that is constantly subject to abuse from children with ink pens, from party goers, and from general wear and tear. Don, being an ad man himself, actually points out that there is a reason white carpets appear mostly just in ads: they are almost impossible to keep clean.
- In Secret Garden at least one of the male lead's houses (he has several) has all white decor.
- The Tarr family in Defiance own a mansion with white walls. They also happen to be part of an alien race that has truly white (as opposed to European-descent "white") skin.
- Boss Hogg from The Dukes of Hazzard wears an immaculate white outfit and is driven about in a white Cadillac, part of his facade as a legitimate entrepreneur. In fact, Hogg has his grubby fingers in every crooked racket in Hazzard County, more deserving of a Satan-red outfit.
- Daredevil (2015): Wilson Fisk spends an absurd amount of money on an all-white painting called "Rabbit in a Snowstorm" in the episode of the same name.
- The Beverly Hills mansion that housed The Beverly Hillbillies had an interior of whites and muted greys, the better to offset the characters. Coupled with the Spartan furnishings, it conveyed an air of opulence succinctly.
- Paying guests arriving at Fantasy Island are always welcomed by Mister Roarke and his servant Tattoo, both wearing immaculate white dinner jackets. Since Fantasy Island can make anyone's fondest dream come true, Roarke's whiteness suggests carte blanche resources at his disposal.
- Black Mirror: In the Christmas Special "White Christmas", one visual tip-off that Greta is rich is that her posh Smart House is filled with very minimalist furniture that is all white or gray.
- Mentioned in the song "Uptown Girl" by Billy Joel:
"Uptown girl/ She's been living in her white-bread world".
- In Sam Smith's "I'm Not The Only One" music video there is a stark contrast between the literally everything is white-ness (including Dianna Agron's hair) of the cheater's idealised home life and the darkness of his late night (lower-class) rendezvous.
- Norway's entry in the 2015 Eurovision Song Contest was Mørland and Debrah Scarlett. The commentary before they began singing said "They're dressed all in white... like they work in a posh, private, hospital. In the future."
- In Battleborn, an occurring color in the colorscheme of a number of LLC characters is white. The sleek shiny white color goes along with their faction being characterized as rich.
- Bungo to Alchemist: Partly because authors of the Shirakaba magazine faction have upper-class and influential family backgrounds and partly because of their name, they all wear white.
- The Schnee Family Manor in RWBY is colored primarily blue and white, with the latter color more prominent in both character design, clothing, and household items like vases and the walls themselves. Not only does the color white represent their affinity with ice, it also shows their richness.
- Apple products, which are notoriously more expensive than their Windows or Android-based counterparts, tended to be initially available only in white. Other colors are generally added to the lineup only later, after the price has dropped. The white iPhone is still, after this drop, more expensive than the black one. This design trend has been mostly replaced with silver metal, but it still tries to evoke the pure white of the Steve Jobs-era product lineup.
- Perhaps inevitably, one of the things Steve Jobs spent the fortune he made in his tenure as Apple CEO was a yacht◊ in the same shade of white as their flagship product.
- The tradition of the white wedding gown began with Queen Victoria. In those days, white dresses were very hard to keep clean, so only the rich wore them.
- Inverted with "white goods" - fridges, freezers, washing machines, dryers, dishwashers etc. The basic models are white with more expensive models available in black, brushed/burnished steel or more exotic colours.
- One UAE billionaire sheikh had a custom-made Mercedes built out of pure white gold.