From this tab you can browse from a list of 5 (November 2011 release) reference dataset experiments. Each reference dataset outlines the stain, the target of the stain as well as the staining pattern.
Selecting the experiment ID will launch a contact sheet viewer. Clicking on individual images in the contact sheet viewer will launch a High Resolution Image Viewer. From the Image Viewer you can adjust the color channels or contrast of the image by moving the slider bars.