Urged by his parents to gain the best education and then turn it into a fight for social justice, he decided to become a lawyer. Having graduated from one of Bogotá’s top law schools, Mr. López turned his sights to Harvard Law School, and was shattered when he was rejected.

That Harvard rejection, however, inadvertently led to his current occupation.

“I was 28, my life was turned upside down,” Mr. López said. “So I went from Cambridge, Mass., to Manhattan to bury my sorrows and blow off steam.”

“In SoHo, I stumbled across such a vibrant graffiti art scene that spoke of social injustice. It was even being sold at galleries,” he said. “That was when a light bulb went on. I thought, ‘Maybe one could do both: spark a social revolution and make a business out of it.’”

Mr. López went home and in 2009 founded Vértigo Graffiti.

“Those first years were difficult,” he said. “We started doing demos for free in private homes to build a portfolio. There was a lot of trial and error as I learned what could be possible. Even though painting on public walls was illegal at that time, there was early interest from some companies. We created a huge campaign with Coca-Cola and Sprite in 2011.”

In the aftermath of a police killing of a 16-year-old graffiti artist that was widely condemned, he helped persuade the city government in 2012 to decriminalize graffiti painting in certain areas.