Students seeking to knock out Redwood Middle School’s strict dress code won the first round Monday, when Napa County Superior Court Judge Raymond Guadagni ruled the students and their families “established a substantial likelihood” of winning their constitutional challenge to the code.

A group of 15 students and parents filed a lawsuit in March with the help of the American Civil Liberties Union, arguing the Napa middle school’s dress code — which bans denim, clothes with logos, stripes and articles of certain colors — violates First Amendment rights and the state educational code. The dress code is the strictest in the Napa Valley Unified School District.

The case has gained worldwide notoriety, in part because one of the students in the lawsuit charged she was disciplined for wearing socks with the Disney character Tigger from Winnie the Pooh stitched on them.

Donnell Scott, a parent of two students suing the NVUSD over the dress code, said she was elated.

“This is a public school and we the people are the public,” she said. “The students have rights and those rights need to be heard.”

The code allows only solid colors in blue, white, green, yellow, khaki, gray brown and black. It bans sweat pants and jeans with only chino, corduroy or cotton twill permitted. It was created by a group of parents and school officials in the late 1990s to address concerns about gang activity on campus.

Sally Jensen Dutcher, a school district lawyer, released a statement saying the district is “reviewing the decision and evaluating the next steps.”

Thomas Loran III, the American Civil Liberties Union lawyer who argued the preliminary motion in front of Guadagni May 23, said the ruling gives him confidence the ultimate outcome of the case will favor the families.

“While I do find that it’s a non-final determination, it’s a strong indicator,” he said.

Guadagni’s ruling said there is no harm in leaving the code in place during the litigation, but still said in his view the code is overly restrictive in its efforts to address gang or discipline problems.

Guadagni cited evidence the dress code prohibited students from wearing breast cancer awareness ribbons and a heart sticker on Valentine’s Day. In his ruling, Guadagni cited a June 25 U.S. Supreme Court decision upholding the suspension of a student for displaying a banner reading “Bong Hits 4 Jesus.”

Even in that case, Guadagni wrote, the U.S. Supreme Court did not stray from the principle that students do not shed their constitutional rights when they enter the school campus.

In that instance, the U.S. Supreme Court held the school was within its right to punish a student for promoting illegal drug use.

Guadagni found Redwood Middle School did not have similar ground to stand on with banning religious speech, cancer awareness ribbons and Disney characters.

Guadagni wrote that he understood the broad reach of the policy was to hinder gang-related clothing and symbols and to quickly identify people who are intruding on campus.

“That this has happened only once, and without any showing that the boys from another school had any gang affiliations, suggests that the policy is not tailored to meet defendants’ legitimate gang-prevention concerns,” the ruling reads.

At the May 23 court hearing, school district lawyers said a preliminary injunction would cause chaos at the school, but in waiting for summer vacation to issue his ruling, Guadagni said the district could supply no evidence to show it would likely be harmed in the same way during the summer break.

Under the law, the plaintiffs now have to put up a $10,000 bond in the event they both lose the case and that the defendants prove they were harmed by the preliminary injunction.

“We’re going to be filing a bond to ensure that the injunction is binding and forceful,” Loran said.