Previous research has shown Dye-Sensitized Solar Cells (DSSCs) to have excellent applicability for building exterior materials and windows, because they can be controlled in terms of Visible Light Transmittance (VLT) and color, and thus have good variability. However, windows with solar cells may not show ideal energy generation efficiency. This depends on a variety of factors, such as window composition, shadow, and light scattering. In this paper, through mock-up tests, the energy generation of DSSCs with various transmittances and colors was measured. Red, Green, and Blue (RGB)-based DSSCs of 7, 10, and 20% VLT were used, and Pmax values were measured for solar radiation for comparison. As a result of the comparison, performance estimates were made for each color and VLT when used as a window. In this study, the electrical energy generated by DSSCs was measured in an environment applied to a real window, not a virtual environment. Therefore, the study is meaningful, in that data that can estimate performance when applying various types of DSSCs in a real-world window environment were created.