It's Pride weekend in San Francisco. Get ready for a lot of rainbows and resistance on Saturday and Sunday. The theme this year is "A Celebration of Diversity."

"We should serve one another not because of our common humanity but rather for our distinctiveness," said Amy Sueyoshi, one of six Community Grand Marshals of this year's San Francisco Pride Parade and March. "Get your queer on and make the world a better place."

More than 20 builders and artists spent Thursday in a Mission Bay warehouse on San Francisco’s Pier 54 painting, sawing, nailing and rigging, tacking boas, attaching styrofoam balls and using a healthy dose of glitter to decorate some of the more than 40 floats expected to make their way down Market Street in Sunday’s parade.

"Because it’s 'Summer of Love,' everybody’s getting into the '60s psychedelic thing, which has been just a blast to work with," said Stephanie Mufson, a veteran float builder.

Mufson roamed the warehouse keeping everyone organized and on task. She was backed up by a count-down clock hanging on the wall, reminding the volunteers that only three days and 20 hours remained until parade time.

"It’s a lot of putting on floral sheeting and trim and things like that," said artist Yulia Rashkovskaya as she prepped an enchanted forest-themed float. "There’s a lot of fabrication: making these giant flowers, making the lips, making this tree out of styrofoam and wood."

Gay pride parades have always been a combination of fun, pride and politics. In 1978, gay activist Harvey Milk led parade protests against Proposition 6, the so-called Briggs Initiative that would have banned openly gay school teachers in California. In other years, HIV/AIDS policies of the Reagan and Bush years were the targets of anger.

Here's a KQED archival video from the 1979 parade, then called the "Gay Freedom Day Parade":

This year, with President Trump in the White House, there will be an especially loud and clear statement about the community’s values.

"Many of us, in fact I’d say most in our community, recognize that resisting Donald Trump is part and parcel of every fiber of our being," said San Francisco Supervisor Jeff Sheehy. He represents the city’s largely gay Castro neighborhood, where Trump got less than 2 percent of the vote in some precincts. Sheehy said part of the message in this year’s parade is that LGBT people are everywhere.

"Some of the first communities that have been attacked, like our Muslim brothers and sisters -- well there’s LGBTQ Muslims, or immigrants. Any community includes LGBTQ folk," Sheehy said.

Ahead of those colorful floats still being prepped, the parade will be led by what organizers are calling a "Resistant Contingent."

"Eschewing the usual floats and music, representatives from about 20 diverse organizations will lead the parade with an all-on-foot march down Market Street," organizers wrote on their website. "Highlighting concerns ranging from women’s rights to immigration policies and the profiling persecution of African Americans, these voices will lead the normally celebratory event with a political statement reminiscent of the very milestone it commemorates -- The Stonewall Rebellion."

The "Resistance Contingent" will include S.F. Black Community Matters, International Migrants Alliance, Indivisible and other groups.

KQED's Peter Arcuni contributed to this story.