The Guardian reported:
The slippers were designed along with all the other costumes for the film by Adrian Greenberg – always just known as Adrian – the chief costume designer at MGM studios, whose favourite childhood book was Frank L Baum's 1900 classic, The Wonderful Wizard of Oz.These aren’t the only ruby slippers to survive from the movie. The studio had several pairs made, two as prototypes and then perhaps half a dozen in the final design. There were pairs for Garland and for her double. There were shoes for dancing and shoes kept pristine for close-ups. Most of those that remain are in private hands. One belongs to the Academy of Motion Picture Arts and Sciences. And one pair was stolen from the Judy Garland Museum in Grand Rapids, Minnesota, in 2005 and is still missing.
In the original screenplay, Dorothy's shoes were silver: scriptwriter Noel Langley is credited with changing this to "ruby slippers", which would give a more striking colour contrast when she is magically transported from black-and-white, storm-torn Kansas to the Technicolor magical world of Oz.
They were made in Los Angeles by a veteran shoemaker, Joe Napoli, from red satin shoes with a one and a half inch heel, covered in red sequins hand-stitched on to fine chiffon, with a centre bow edged with red glass beads and crystals. Visitors to the exhibition may be surprised to see that they are actually a deep winey garnet colour, designed to photograph as scarlet in Technicolor.