Randall Mays, businessman, investor, and philanthropist, knows how to throw a good party—if your idea of a party involves meditating on grass under open skies (the kind you sit on, not smoke). Interior designer Christina Simon of her eponymous Austin studio can attest to Mays’s definition, having had a hand in transforming his circa-1915 bungalow in Travis Heights, Austin, into a space that’s grandpa-chic by day and trippy by night. “It serves as a lively venue for hosting parties during SXSW and the Austin City Limits Music Festival,” says Simon, whom Mays found through artist friends and enlisted with a brief of exactly four words: Austin eclectic hippie vibe, please—five, if you’re being precise.As Simon recalls, the brief was, fortuitously, easier done than said. “The home was lovely, but it was really disjointed and everything was white. It was a blank canvas,” adds the designer. She worked with Daniel Ward of Mark Richardson Architects and Dustin Minium of Red Tail Construction for the architecture and execution.The living room—awash in Farrow and Ball’s Inchyra Blue—is a curated library of vintage finds, featuring an original Rex Ray rug, Dunbar glass coffee tables, and Knoll’s Wassily chairs (right). Simon designed the sofa to fit perfectly into the window alcove and framed the adjacent wall with a grid of small-scale paintings by Texas artist Matt Kleberg. Overhead, an Il Sol flushmount light by Paul Ferrante casts a warm glow, while a CB2 chair to the left provides a cozy perch. Art: Matt Kleberg/Josh Pazda Hiram Butler GalleryA canvas this blank would typically take time to fill—but time was a luxury Simon didn’t have. “The renovation happened in two stages—paint, wallpaper, countertops, and surface areas before Randall moved in, and then the full bath and kitchen remodel after. We had about two months for the ‘before’ bit, so everything we ordered had to be in stock—it was very tight, a little unnerving, and a small miracle,” she says. Lucky for her, she knew where to start. “Randall is an artist, an art collector, and a true bon vivant. His homes are always open, whether he’s there or not, so I designed a space as fun as his legendary parties—full of conversation nooks that spark dialogue and the laid-back hospitality his gatherings are known for, from season to season, day to night.”She designed the home in bold layers, enlivening some walls with grasscloth, moiré silk, and walnut veneer wallpaper, and others in deep, brooding blues and purples. “Wherever we could build texture and warmth, we did,” adds Simon, who opted for characterful textured window coverings and warmed the sunroom in Clé’s black terra-cotta tiles. As for the decor, she leaned vintage. “That’s how I started getting the look and feel down for the house,” Simon adds.Mays’s office is anything but traditional. “It turned into an explosion of creativity and psychedelic references—the whole space transforms under black light,” says Simon, who brought in vibrant cushions, a mural by Austin artist Michelle Marchesseault, and a surround sofa and ottoman of her own design, upholstering the former in Opuzen’s Furocious fabric. “Oranges and pinks glow against iridescent mushrooms, third eyes, and hidden Easter eggs—nods to the client’s family, their love for dancing bears à la the Grateful Dead, and inside jokes only they would recognize.” Art: Michelle Marchesseault/Northern-Southern