Sporting a large white mohawk, wearing a neon green tank top and carrying a purple, pink and blue sign bearing the words "Love is Love," Dave Watt was all smiles.

It was his first time leading New Orleans' annual Southern Decadence parade, and he was spreading the message that anyone who has HIV should be allowed to live stigma-free.

Watt, the leader of the HIV-awareness group Mr Friendly, said he landed the coveted spot in the parade because one of the grand marshals was so enthralled by his organization's message.

"This is a once-in-a-lifetime opportunity," he said. "I'm thrilled."

The activist was one of hundreds who took to the streets of the French Quarter on Sunday afternoon to celebrate gay pride during the 47th annual Southern Decadence marching parade.

More than 50 groups joined the parade, which was open to anyone, LGBTQ and not.

Presiding over this year's parade as grand marshals were drag performers Princesse Stephaney, Coca J Mesa and Persana Shoulders.

With the theme "Electrified," the official parade colors were "anything neon."

As they danced, marched, roller-skated and twirled passed several gay bars, parade participants also wore large white Marie Antoinette-themed wigs, white lace gowns, hot pink corsets and lots of feathers.

Neon rainbow hoop skirts, tutus, tie-dyed flags, miniskirts and fans were also popular, as were black leather accessories and various kinds of masks.

Southern Decadence — also called the "gay Mardi Gras" — started in August 1972 as a simple going-away party, according to its website.

A group of friends living in "a ramshackle cottage house" in Treme decided to throw a going-away party for one of their number. The residents had named the house Belle Reve, in honor of Blanche DuBois' Mississippi plantation, because of the friends' tendency to read Tennessee Williams' play "A Streetcar Named Desire" out loud.

The very first Southern Decadence, documented by author James T. Spears in "Rebels, Rubyfruit and Rhinestones: Queering Space in the Stonewall South," began as a riff on the "Belle Reve" theme when the group named the going-away costume party a "Southern Decadence Party: Come As Your Favorite Southern Decadent." 

The following year, the group decided to throw another Southern Decadence party, this time with a walking parade of about 15 people. The first grand marshal was named in 1974.

Since then, the annual Labor Day weekend event has evolved into one of New Orleans' largest celebrations, with an economic impact that ranks it among the city's top five tourist events, organizers say.

They say it attracts more than 200,000 participants, predominantly gay and lesbian, and generates over $250 million in tourist revenue.

While Sunday's parade is the main attraction of Southern Decadence each year, the party kicked off in earnest Thursday night with a midnight dance party at the Bourbon Pub.

The celebration continued Friday night with "Boys on Parade," an amateur strip night, also at the Bourbon Pub.

Saturday's events included a free outdoor concert at Bourbon and St. Ann streets and a 9 p.m.-to-dawn festivity called "The Black Party."

Decadence is slated to end on Monday with a "Hung Over and Broke" closing party.

Although the nighttime Southern Decadence parties tend to be adults-only, Saturday's parade attracted thousands of spectators young and old.

Among them were the Courtney siblings — 25-year-old Caleb, 24-year-old Josh and 18-year-old Sarah — who grew up in Houma but all moved to New Orleans to feel more accepted.

"Everything has been very peaceful and loving," said Caleb Courtney, who wore a handmade beaded dress, a gold necklace and rhinestones on his face.

Isaac and Amanda Toups, the owners of Toups' Meatery, agreed. They had brought their daughters, 6-year-old Poppy and 3-year-old Ivy.

"Love is love is love," Amanda Toups said, adding that Ivy was enthralled by all the "princess" costumes she saw. "If they're indoctrinated at a young age, they'll never feel differently."

French Quarter activist Leo Watermeier said later that one member of a small group of “street preachers” who often come to New Orleans to protest during Southern Decadence was arrested during the parade.

Watermeier said the unidentified preacher "apparently was seen by a state trooper assaulting a female parade bystander." 

The street preachers carry signs with messages such as "Homo sex is sin" and "Jesus saves from hell." They often use bullhorns to denounce homosexuality and festival participants.  

Follow Della Hasselle on Twitter, @dellahasselle.