As players around the league honor Dr. Martin Luther King Jr. on Monday, they'll wear special-edition warm-up shirts made by Nike that feature some of the pioneer's most iconic "I Have A Dream" speech quotes. In addition, players such as Kyrie Irving, LeBron James and James Harden will sport an array of themed sneakers paying tribute to the civil rights leader.

During recent seasons, special-edition sneakers have become more prevalent. The NBA has loosened the restrictions on staying within a team's uniform palette, allowing for players to showcase their personalities, express their style or even honor a person or cause close to them. For an event like MLK Day, sneaker brands often create layered product capsules to raise awareness and benefit community programs.

"Our group started looking at this stuff in the mid-'90s," said Christopher Arena, the NBA's senior vice president of identity, outfitting and equipment. "Back then, the rules were you had to have the majority of the shoe in black or white. 51 percent has always been the number that's been thrown out. The basis of that was to create some form of team unity."

Historically, that meant that players on all teams hit the hardwood in matching predominantly white or black sneakers, with allowable accents only in the team's colors. It wasn't until the turn of the century that color became more noticeable through footwear at All-Star Weekend.

The game's biggest names and signature athletes could flood their shoes in the defining shade of their franchise, or wear red or blue to match each All-Star Game uniform. The best examples early on were Kobe Bryant's all-yellow pair of his Adidas The Kobe model, Vince Carter's shimmering silver and red Nike Shox BB4 and Tracy McGrady's red and royal mismatched patent leather Adidas TMac 3. Then-Kings star Chris Webber raised the bar with an all-chrome pair of his signature CDubbz. Soon after, brands began creating special-edition themed sneakers highlighting the local culture or elements of each year's host city.

The league watched closely to see the response from fans and the excitement from players. Although the league began to incorporate gray into the allowable palette for sneakers worn in the regular season at the start of the decade, it wasn't until the 2009 season when the rules really opened up, moving away from the longtime 51 percent white, black or gray guidelines.

"The unity wasn't necessarily that we were all 51 percent of one color," Arena said. "The unity is that the players are all matching their team identity."

The progression of color evolved even further in just a couple of years, as the 2012 season brought with it a series of moments throughout the 82-game calendar that allowed for even more expression.

"As we saw [All-Star Weekend] take off, we started to get into what we call our event policy for footwear," Arena said. "We said, 'Let's align these events with the colors of shoes.'"

The Equality sneakers worn by LeBron James on opening night were allowed in part because of the NBA's theme nights, which allow players to wear gold-accented shoes to open the season. David Liam Kyle/NBAE via Getty Images

The number of event-policy games, often simply called theme nights, can fluctuate from season to season depending on the league's ongoing initiatives and different featured campaigns. This year, there are 10 windows when the guidelines are nearly thrown out, allowing players to bring their own special-edition looks and themes to life.

Gold accents on footwear can be worn on trophy/ring/banner night, the season-opening celebration game for the league's defending NBA champion. Shortly after, Halloween kicks things off for what the league describes as an any-color-combination game. What started out as a theme night allowing for pumpkin-inspired sneakers soon saw everything from glow-in-the-dark Stephen Curry shoes to pairs inspired by classic horror-film characters.

"Listen, we're not going to be the judge or jury on what designates a Halloween shoe," Arena said. "I don't know that Halloween is just black or orange. Zombies, spiders and ghosts are related to Halloween, and all of those things aren't necessarily orange."

Unlike in the NFL, which requires brands to pay a logo-visibility fee to appear on the field, NBA players can wear any brand's sneakers in games. There is, however, a detailed review process for sneakers to still be pre-approved by the league to ensure there aren't any mechanical parts that might create a performance advantage, any protruding parts that could fall off midgame or injure someone, or any gleaming or reflective parts that could distract a broadcast audience.

"We understand the footwear industry, and a lot of these shoes are pre-built far in advance, but oftentimes there might be some shoes that come up as a one-off," Arena said. "We're certainly open to take those and review them accordingly.

NBA 2017-18 Event Policy dates Oct. Opening Week Oct. Halloween Nov. Hoops for Troops Dec. Christmas Jan. MLK Day Feb. Black History Month Feb. All-Star Weekend Feb. Chinese New Year March Noches NBA June NBA Finals

"As long as there's no corporate advertising, if guys are honoring someone and might write in Sharpie, we'll look at that on a case-by-case basis. If there are charitable elements, we want to make sure that those charities are real and relevant. That's really it."

The full event-policy calendar also includes a weeklong allowance for red, white and blue sneakers during the league's Hoops For Troops campaign in November. All throughout February, players can celebrate Black History Month through any color theme of their choosing. The Chinese New Year window allows for added hues of red and yellow, and the annual "Noches NBA" period in March shines a light on the league's largest Latin American markets with special team uniforms and loose color restrictions.

As the 10 windows of theme nights add some fun to an already player-friendly league under the Adam Silver-guided era, there's also a little-known nuance to the rules that most players have yet to take advantage of: the guidelines don't actually apply at all during the preseason or during pregame warm-ups.

When it comes to the 82-game schedule of official games, the league actually reviews every game shortly after for any issues. Should a sneaker or theme not comply, typically the league's outfitting department will contact a team's equipment manager first, notifying them of the issue and working to fix it.

While thousands of different colorways from a variety of brands may hit the court during a regular season, the warnings have been few and far between since the NBA began its color restrictions. More recently, Carmelo Anthony's Jordan Melo M10 sneaker in 2014 featured a chrome heel that the league requested to be altered. The brand made him a batch of updated pairs shortly after, with a heel piece that featured a matte paint finish instead.

"I'm not sure that we're ever going to stop a game, call a timeout and make a guy change his shoes," Arena said. "We're not going to do that, certainly."