Redwood Middle School’s controversial dress code is heading to the California Court of Appeal, even before there is a final ruling in the legal challenge to the code brought by several Redwood parents and students.

The Napa Valley Unified School District has decided to appeal Napa County Superior Court Judge Ray Guadagni’s preliminary injunction, temporarily suspending the dress code at the north Napa middle school. Guadagni held earlier this month that the parents and students had a good chance of winning on their claim that the code violates free speech rights of students.

The decision to appeal could net the school district the legal ammunition it needs to keep the dress code intact while the litigation continues. If the district loses, however, it could further unravel the school’s case.

The American Civil Liberties Union filed a suit on behalf of local families in March, charging the Redwood Middle School dress code violated the U.S. and state constitutions, as well as the state education code. The dress code bars students from wearing denim, stripes, corporate and other logos, and clothing of specific colors.

One student was found in violation of the code for wearing socks embroidered with the Winnie-the-Pooh character Tigger.

The school district has argued that its dress code is appropriately tailored to provide a safe learning environment for students.

In a Tuesday statement, school district lawyer Sally Jensen Dutcher remained optimistic the school would come away from the lawsuit with the dress code intact.

“We believe that when all litigation is complete, there will still be a legal Appropriate Attire Policy in effect at Redwood Middle School,” she said. “We are appealing at this time to bring the issue of what students may wear in middle school to the appellate court.”

Redwood Middle School’s code is the strictest in the school district, allowing 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 pants permitted. It was created by a group of parents and school officials in 1998 to address concerns about gang activity on campus.

With the appeal, the school district will continue to “explore all available avenues” to bring the lawsuit to a close where the district can focus on “ensuring that every student receives the highest quality education,” according to the school’s press release.

Julia Mass, a spokeswoman with the ACLU, said the organization had hoped the school would accept Guadagni’s ruling.

“On the one hand we would welcome a written opinion on the court of appeal reaffirming the Napa court’s decision,” she said. “We feel that the judge in Napa did a good job of explaining his legal reasoning and the evidence he was relying on. I am disappointed that the district hasn’t decided to resolve the case and allow students to express themselves at the school in accordance with the U.S. and California constitutions.”

The Napa Valley Unified School District board of trustees grants each school the chance to adopt a dress code that suits campus needs, saying it “believes the policy has fostered a safe environment while minimizing serious gang influences.”

As the case moves through Napa County Superior Court, lawyers will do more legal fact-finding and refine their arguments. The school district is hoping that will change the tide of the lawsuit in their favor, saying Guadagni decision to grant a preliminary injunction “short circuits that process.”