Manufacturer Hummel said the kit has a "dual message" to support the team and protest against Qatar's "human rights record".
Denmark will wear kits at the 2022 FIFA World Cup to protest against the human rights record of host nation Qatar.
The Danish manufacturer Hummel unveiled the team's new strips on Wednesday, including a black third-choice design.
“The colour of mourning,” Hummel said in an Instagram post, "The perfect colour for Denmark's third shirt for this year’s World Cup."
"While we support the Danish national team all the way, this shouldn’t be confused with support for a tournament that has cost thousands of people their lives," the company said.
"We wish to make a statement about Qatar’s human rights record and its treatment of the migrant workers that have built the country’s World Cup stadiums."
Last year, Denmark's football federation had pledged to wear clothing with “critical messages” at the upcoming tournament.
Under FIFA's rules, countries can face disciplinary action if they feature political statements or insignia on team uniforms.
To comply, Denmark's three designs -- in red, white, and black -- feature no words or symbols as an explicit statement. Instead, the national team badge, Hummel logo and iconic chevrons are faded into the same single colour as the shirt.
"We don’t wish to be visible during a tournament that has cost thousands of people their lives," Hummel said on Instagram.
"We support the Danish national team all the way, but that isn’t the same as supporting Qatar as a host nation," it added.
"We believe that sport should bring people together. And when it doesn’t, we want to make a statement."
Several European nations -- including Germany, the Netherlands, and Norway -- wore protest t-shirts before FIFA World Cup qualifiers last year.
The Danish federation also joined a European campaign launched last week for captains at the Qatar World Cup to wear heart-shaped, multi-coloured “One Love” armbands in World Cup games.
Danish officials have taken a leading role in a group of European soccer federations visiting Qatar to monitor the progress of promised reforms in labour laws.