Republican candidates wore red ties at the first GOP debate. A stylist called it the 'Trump look-alike effect.'

The color red became associated with the Republican party during the 2000 election, when newspapers such as USA TODAY printed full-color election maps for the first time. The terms "red state" and "blue state" also became part of the lexicon that year to describe states won by Republican and Democratic candidates, according to Smithsonian magazine.

Parodies of Trump often feature the character in a red tie. The official Trump store also sells red silk ties for $125.

Lauren Rothman, a corporate and political fashion stylist, image expert, and author of "Style Bible: What to Wear to Work," told Insider that while many politicians have gravitated towards red as a camera-friendly color, Trump made it his brand.

"If we can come to rely on your look, we see you before we see you, and we hear you on mute," Rothman said. "Trump really embodied that formula, which has been in place for a long time for politicians."

Republican presidential candidates Asa Hutchinson, Chris Christie, Mike Pence, Ron DeSantis, Vivek Ramaswamy, Tim Scott, and Doug Burgum attended the first debate of the GOP primary season wearing matching red ties. Nikki Haley, the only woman onstage, was also the only candidate not wearing the look since she was not wearing a suit.

"They got the memo of what works on a Fox screen and the power of those visual cues when a lot of people are watching you, whether it's from a bar stool on a big screen or at home over teenagers talking," Rothman said. "You saw it last night if it was on mute or not."

In August 2015, the top 10 GOP candidates appeared for their first prime-time debate in Cleveland, Ohio. Trump wore his usual red tie, as did Marco Rubio and Rand Paul. Ben Carson and Jeb Bush wore a more muted red, while Chris Christie, Scott Walker, Mike Huckabee, Ted Cruz, and John Kasich went with cobalt blue.

John Huntsman and Rick Santorum wore red ties. Mitt Romney, Ron Paul, and Rick Perry wore blue. Newt Gingrich stood out in yellow.

John McCain, Fred Thompson, Ron Paul, Mitt Romney, Mike Huckabee, and Rudy Giuliani wore muted blue and taupe tones.

Trump did not participate in Wednesday's debate. Instead, he sat for a pre-recorded interview with former Fox News host Tucker Carlson that aired at the same time. Nevertheless, moderator Martha MacCallum asked the candidates questions about the absent candidate, such as whether they would continue to support him if he were convicted in court — most said they would.

"As far as I know, there is not a ton of behind-the-scenes consulting about what other candidates are going to be wearing," Rothman said. "My sense is that each one of them came to this separately, not with the intention of a 'squad style.' Nonetheless, that's what we saw, because this is what's being created, right? This is the Trump look-alike effect."