Young men sell football merchandise at the side of the road into central Cape Town, South Africa, on Sunday. ((Dan Kitwood/Getty Images))

The "rainbow nation" is showing its colours ahead of the World Cup, and they're coming in all sorts of tints and hues.

With the opening of the World Cup four days away, street vendors in Johannesburg are out in force selling national flags from all 32 participating countries.

"The World Cup is great, great, great thing for us," said Nathan Murindagamo, a 24-year-old unemployed South African who is now making money by selling flags on the streets. "People are prepared to spend money. Everybody is happy."

Murindagamo said sales of the flags of Brazil, the Netherlands, Spain and Portugal are following close behind host South Africa.

Large flags cost about $20 US, and vendors can make $100 on a good day.

"I left my previous job because I can make more money this way," said Lovemore Toronga, a 30-year-old local standing at a busy intersection in Johannesburg on Monday. "Until the tournament finishes [on July 11], I will continue selling flags at robots [traffic lights]."

Although vendors continue to sell scarves and vuvuzelas -- the plastic horns that caused a ruckus with television broadcasters at last year's Confederations Cup -- it's national flags that can be seen waving in the wind all over the city.

Cars are speeding through the busy streets of Johannesburg with the blue and white Greek flag flying from a window, and restaurants and bars proudly display their roots with the red and green Portuguese flag, or the green, white and red Italian flag.

Of course, the colours that make up the South African flag are everywhere, even on rearview mirrors. Murindagamo said the flags of Brazil, the Netherlands, Spain and Portugal are following close behind in sales.

Many South Africans are counting on the World Cup to create an economic boom in the country. More than 40 per cent of South Africans live below the poverty line set by their government and a quarter of the work force is unemployed. But the World Cup is helping people like Toronga and Murindagamo to better care for themselves and their families.

"I am selling a lot. It is good," Murindagamo said. "The World Cup is helping to unite our country."