Gunmen opened fire on a group of people, among them 26-year-old Gilberto Hernández, who had gathered in a building in the city.
Hernández died and seven others were injured in the attack.
It is not yet clear if the footballer, who also played for Club Atlético Independiente, was the target of the shooting or what the motive was.
There has been a rise in murders in Colón over the past months as two rival gangs fight for control of lucrative drug smuggling routes.
So far, more than 50 people have been killed in Colón, a city of 40,000 inhabitants, so far this year.
The port city, on the north entrance to the Panama canal, is a transit point for cocaine smuggled from South America through Panama to Europe.
The shooting happened on Sunday afternoon local time.
Two gunmen forced a taxi driver to take them to a building in the city’s Barrio Norte neighbourhood and opened fire on the group gathered there.
The gunmen fled the scene.
Gilberto Hernández had made his debut in the Panamanian national side in March this year in a match against Guatemala.
The player’s father urged the youth of Colón “to stop the violence”, and called on the authorities to “launch projects to save the youth from this violence”.
He also asked the killers to hand themselves in: “Don’t cause more harm.”
Panama’s football federation and Gilberto Hernández’s club expressed their condolences to his family.
