Many of the most colorful and fondly remembered children’s series of the 1970s and 1980s sprang from the imaginations of Sid and Marty Krofft. Their groundbreaking, live-action fantasy shows were mainstays of the Saturday morning airwaves, which had previously been the exclusive domain of cartoons. To this day, DVD box sets of beloved Krofft creations “H.R. Pufnstuf,” “Lidsville,” and “Land of the Lost” are brisk sellers, a testament to the artistry and charm of the Krofft brothers and the magical spell they cast on generations of TV viewers.