Color interaction is a perceptual effect that will influence how color combinations appear to an observer. Two main categories are color induction and color assimilation, the former when two colors become more different looking, and the latter when two colors become more similar looking. Typical examples are presentations of web pages on computer displays, cartographic pictures and maps, artistic displays such as paintings, and of environmental images, such as colors on houses. In this survey of concepts and research, the focus is on fundamental issues and definitions regarding these effects. The emphasis is on modern types of displays and relevant characteristics of different technologies are also given. Some historic perspectives are included. Different color appearance models and how they take color interaction into consideration are discussed, also including information on suitable possible color adjustments that the models may give. References are made to modern visual perceptual theories, and the place of these effects in a broader perceptual theory is considered. A number of illusions and pictures that illustrate interaction effects are included. As an example an experiment with perceived interactions between geometrical objects is described in short. Six observation colors and three interaction colors for each observed color were presented to ten observers, who performed a matching task. The result of this study is presented as color interaction diagrams in the CIELUV color space. The importance of color and color interaction in different applications is discussed together with a set of guidelines. The advantages and disadvantages that may result from using the guidelines are addressed. Some concluding remarks on possible future work in color interaction are given.