Technicolor brought a lot of change to movies, and The Wizard of Oz is one of those that helped it make its way along. Unfortunately as most people don’t know, the Wizard of Oz wasn’t the first film to be introduce technicolor in the mainstream. The process of using technicolor was increasingly difficult back in the day. A technicolor camera would use a prism to shoot a picture, splitting the light into different colored negatives that would then be flipped into positive matrices before different-colored dy
Source: This History of Technicolor and How it Changed Movies