In celebration of the team's post-season success, a number of San Francisco buildings have been lit up orange, including City Hall, the War Memorial Opera House and Coit Tower.
The orange effect is the result of filters, or "gels," that are placed over existing lights.
"It's like a transparency from math class that math teachers used to write on, except it's colored," said Mike Kuhlmann, director of event design for the San Francisco company Got Light?.
The gels have to be put in place light-by-light by private contractors, which makes for quite a project at City Hall, where access can be tricky, building manager Rob Reiter said.
"They can't just go out on the balconies without access," Reiter said. "They're going through supervisors' offices, that sort of thing."
The cost of lighting City Hall in a specific color is about $4,000, said Francis Tsang, a spokesman for the mayor's office. The money comes from a "special events" fund made up of private donations intended to promote San Francisco, he said.
"It's kind of a celebration fund," Tsang said.
Kuhlmann said Got Light? didn't illuminate City Hall this time around, but it did create the orange glow at the Alcatraz lighthouse and the Conservatory of Flowers.
Kuhlmann installed the Conservatory of Flowers gels himself, and as a Giants fan he said it feels good to have contributed to the city's excitement.
"When you see someone comment on it, or stop and look at it, it's cool to know that we did that," he said.
Mayor Gavin Newsom today declared a "Giants Pride Week," which will begin Wednesday. He encouraged fans to wear orange and black, and businesses to display Giants signs and flags.
"Let's show the world San Francisco is a true baseball town and help boost this remarkable team to a world championship," Newsom said in a statement.
He said the Ferry Building and Embarcadero Center will soon be lit up in orange as well, and a Giants flag will continue to fly over City Hall.