Pink is the new orange -- ex-Playboy Playmate Colleen Shannon is back on the party scene after her recent prison stint ... celebrating her release with a weekend full of champagne-fueled ragers ... and we got pics.
TMZ broke the story ... Shannon was sentenced to 4 months in federal prison after trying to sneak her BF across the Canadian border last year. She pled guilty to transporting an alien.
But last weekend, Shannon made up for lost time -- partying 3 DAYS STRAIGHT -- Thursday at 340 Nightclub in Pomona, Friday at The Attic in Hollywood, and Saturday at Industry Nightclub in the City of Industry.
Shannon was officially released from prison on March 31, but since her birthday is April 14 ... we're told she postponed her release parties in order to celebrate both occasions.
Shocker ... her boyfriend was not present.