Why, you ask? Four Stanley Cup championships, of course.
It's a subtle change, but supremely important to the past, present and future of the franchise.
"They're really cool to wear," Islanders rookie Josh Bailey said, "especially for young guys because it's a little bit like being part of the team's great tradition."
Tradition is at play in a lot of the third jerseys being unveiled this season across the NHL. Tuesday night, the Flyers will become the latest to show off an old-school third jersey, which is a version that harkens back to the days of the Broad Street Bullies.
The Islanders, Buffalo Sabres, Edmonton Oilers, Pittsburgh Penguins, Toronto Maple Leafs and Vancouver Canucks also are wearing threads that represent the old school in a handful of games this season.
"It brings you back to guys like Gilbert Perreault, Rick Martin and Rene Robert," Sabres center Derek Roy said of the famed "French Connection" line and its association with the team's new third jersey. "It brings the legacy of the Sabres back."
The new school hasn't been forgotten, either.
The Dallas Stars are unveiling a new look today. The Carolina Hurricanes, Atlanta Thrashers and St. Louis Blues already have done so. The Chicago Blackhawks also have sported a unique look, separate from the retro jerseys they will don in the Winter Classic on Jan. 1.
"I think it mixes both the past and the future, but at the same time it's not as if we're messing with (a good thing) too much," Blues forward Brad Boyes said of the team's new jersey. "We're leaning more on something different … we're not changing the whole thing."
The Blues third jersey, which sports a crest with the traditional blue note backed against the city's famed Gateway Arch, is a nice gesture to the city the Blues have called home since 1967.
Six more third jerseys are still to come, the details of those jerseys to be announced in coming days.
"It's terrific that the original uniform is being brought back and celebrated," said Edmonton President of Hockey Operations Kevin Lowe, who scored the first NHL goal in Oilers history in a jersey resembling the one the club debuted last month. "All of the things we take so much pride in today were accomplished in that uniform."
Third jerseys became popular in the late 1990s, and ever since every team but the Detroit Red Wings and New Jersey Devils have sported something unique for at least a handful of games.
The Red Wings, though, will wear a throwback jersey for the 2009 Winter Classic, just as the Penguins did last season. The Penguins brought back that immensely poplar baby-blue sweater, which date to the team's inception in 1967, as a third jersey this season.
The Penguins didn't change to their current black and gold until Jan. 30, 1980.
"I like the dark blue and the (light) blue. It's a little bit different than your usual jersey."
-- Kris Letang
Chris Smith, who operates the Web site www.Icethetics.info, which is dedicated to the aesthetics of hockey, such as jerseys and logos, said he's been following the development of the third jerseys since the summer.
In an e-mail to NHL.com, Smith wrote, "Overwhelmingly fans seem to love the throwback third jerseys. They don't sound happy about the new-style jerseys we're seeing with Atlanta and Ottawa (what's been leaked anyway) -- though fewer complaints for Tampa Bay's. They love what the Oilers, Islanders, Canucks, Penguins and Sabres are doing and I can't say I disagree."
Smith also wrote that the fans "would actually prefer to have (the throwbacks) as primary jerseys. However, I think a lot of them like seeing teams use an alternate color, like Carolina, Tampa Bay and Philadelphia."
"They look real sharp," Hurricanes forward Eric Staal told the Raleigh News and Observer.
Smith's least favorites are the third jerseys of the Thrashers and Stars.
The Thrashers have a dark red jersey with the team name written across the chest, just above a large uniform number. Similarly, the Stars' jersey is plain white with the word Dallas written on the front, above the uniform number.
[Photo Gallery: Thrashers present third jersey to WWE's Chris Jericho]
"I think more people would have embraced the Code Red marketing for Atlanta's third if they had gone with one of the team's logos on the front instead of the text," Smith wrote. "However, this is from a more general perspective; for the most part fans of each individual team seem more or less happy with their new alternates."
Contact Dan Rosen at email@example.com.