Sepia Toned Kansas
When Dorothy sings “Over the Rainbow,” she invokes images of a land “where troubles melt like lemon drops/Away above the chimney tops." Meanwhile she is leaning up against a haystack in the sepia-tinted world of Oz. A contrast emerges between the colorful and fantastical universe she is describing in the song and her drab surroundings. The Kansas prairie is dusty and expansive, and the directors create the effect of its monochromatic quality by choosing to shoot it in black and white.
The Emerald City
The Emerald City is a distant specter for Dorothy and her companions when they first emerge from the forest. The four companions look across a giant field of poppies at the green metropolis in the distance. Then, when they arrive, they enter into a monochromatic world of green. Everyone in the Emerald City wears green clothes and the walls and floors are green as well. The only color that diverges (besides Dorothy and her friends) is the color of the horse pulling their carriage, known as "the horse of a different color." The horse changes colors several times, and according to film history, if one looks closely, one can see the horse licking off the dye that it has been covered in.
Dorothy coming out of the house
One of the most iconic visual moments in film history is the moment in which Dorothy emerges from the house after it has landed with a thud in Munchkinland. Hitherto, the film has been in black-and-white, but when Dorothy opens the door out into the world of Oz, our eyes are met with a feast of color. By delaying the introduction of Technicolor until the moment that Dorothy comes out of the house, the filmmakers create a special effect for the viewer: it is as though we are seeing color for the first time along with Dorothy. The effect is nothing short of magical, and it foreshadows the fantastical elements that will emerge in the rest of the film.
The Ruby Red Slippers
Many changes were made in the leap from the page to the screen, but the most obvious has to be the transformation of the slippers from silver to red. Of course, the primary reason for this change is that the filmmakers wanted to show off the Technicolor process to its full effect, and red helped them do that. The ruby slippers glimmer and gleam in the light, and they have become an iconic relic of film history. Their bright ruby color pops in relation to all the other colors in the film, particularly the gold of the yellow brick road.
