The Spectral Edge method of image fusion fuses input image details, while maintaining natural color. It is a derivative-based technique, based on the structure tensor, and lookup-table-based gradient field reconstruction. It has many applications, including RGB-NIR image fusion and remote sensing. In this paper, we propose adding an iterative step to the method. We use the output Spectral Edge image as the putative color image for another fusion step, and repeat this for several iterations. We show that this creates an output image with a structure tensor field closer to that of the high-dimensional input than the output of the original method. We perform a psychophysical experiment using the iterative Spectral Edge method for RGB-NIR image fusion, which shows that the result of multiple iterations is preferred.