In the black room, the dim light barely illuminated the undulating sofa. Through the slanted view modules you could glimpse a galaxy far away from the Milky Way. Obviously, time and space had made a jump at Warp Seven speed. The time is the future. The place is a space colony out there . . .

With this futuristic model room, Woodward & Lothrop looks forward to its second hundred years in Washington. This glimpse of the furture and five other model rooms meant to mark the last 100 years were previewed at a benefit gala Saturday night that brought Friends of the Kennedy Center from all over the country.

Edwin K. Hoffman, chairman and chief executive of Woodies, with actress Mary Martin (in a rose dress) on his arm, welcomed guests. Television's "Dallas" star Mary Crosby, in chiffon, traveled around the room with William McDonald, Woodies' vice president of sales promotion. (Martin, by the way, is the mother of Larry Hagman, "Dallas'" J.R.)

Roger Stevens, head of the Kenndy Center, and Lily Guest, chairman of the Friends, stayed busy welcoming out-of-town Friends such as Alice McKiney, Indianapolis, Ind., a member of the President's Advisory Council for the center.

Eleven ambassadors and their wives were there. The Irish ambassador and Mrs. Sean Donlon admired the Sybil Connolly fabric in one of the room settings, supervised by Claus Mahnken. They're giving a party for the Irish designer tommorrow. Brazilian Ambassador and Mrs. Antonio Azeredo da Silveria, according to Mrs. McKenzie Gordon, wanted to meet Mary Martin because she owned a vast estate in Brazil.

Bruce Ellis, one of the twin owners of Ridgewell's Caterers, took a turn at griddling a slice of gyro meat for the pita bread sandwiches. Raymond Howar, the developer, explained to Scooter and Dale Miller just how you scooped seasoned yogurt, tomatoes and onions into the pocket bread.

Guest sipped champagne on the first floor, watched magician David Willis on the third, listened to a harpist on the fifth, and danced to everything from big band tunes to rock 'n' roll on the sixth.

Meanwhile, mines, who seem to be as necessary these days for department stores parties as lavish buffets, fitted about in unsettling poses.

The most cheerful people at the party were the model room designers, including Jack Dorner, who, with Katie Brown and Rebecca Prillaman, were responsible for the "Future Space" room. They had worked until the last minute. Dorner even raided his own house for objects for the room.

And just to sweeten the goodbyes, guests left with party favors of centennial paperweights, boxes of Godiva chocolate and, appropriately, umbrellas to keep off the night's rain.

Woodies wasn't alone in showing off model rooms on Saturday. The National Symphony Decorators' Show House had a party for the Women's Committee who sponsored the house and the designers of the rooms in the Rittenhouse Street mansion. Through the night was wet, the tent, full of wine, punch and cheeses, was dry and cheerful.