One distinctive feature of model robot kits since the 1990s, as opposed to most other plastic model kits, is that they are molded in color: each part generally is made of a colored plastic corresponding to its intended color on the finished model. Bandai in particular has become well-known for its use of multi-color molding, which allows parts of different colors to be molded on the same sprue. In some cases, compromises have to be made - for instance, molding a part in an incorrect color, or a two-colored part in only one color - to ensure that the model is structurally stable and not overly complex, particularly when the intended retail price is low. One criterion by which enthusiasts assess the quality of a kit is its color-accuracy - that is to say, the correspondence between the molded color of the parts and the intended color of the finished model.