Owing to a limited display resolution, it may be difficult to obtain an overview of high-dimensional data in the display area used for visualization. In this paper, we aimed to obtain an overview of high-dimensional data in a limited screen area. We developed Colored Mosaic Matrix as a method to obtain a data overview. Colored Mosaic Matrix is a visualization method for high-dimensional categorical data that uses a color representation of the features. By representing quantitative data in category units, the proposed method enables the visualization of data containing a large number of records. As a result of an experimental investigation of its readability, we found our method to be useful in obtaining a data overview.