Hi all. I am attempting to merge multiple data sets using the georeference mosaic tool. Specifically, I have a large gray scale base image and 3-band RGB file I have overlayed with the RGB representing three mineral units. Setting the RGB files "Data Vale to Ignore" to the zero value of the RGB allows only the non-zero mineral pixels to show up great in the mosaic window. However, when I apply the mosaic creating a new file everything is georeferenced properly except the colors have been messed up? I think the grayscale image is being combined with the green channel in the RGB? Different combinations of “Color Balancing” setting for the RGB produce different erroneous mosaics. How can I avoid this? Again, I want the RGB overlayed on the grayscale with zero set to transparent. I am running ENVI 4.5 but have access to 4.8. Thanks, Matt