The NASA image above (click to zoom) shows the Great Lakes in Autumn 2011. The image is again from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite. Lake Michigan and Lake Huron are coloured light blue from sediment brought to the surface by winds, while Lake Erie is coloured green by a severe algal bloom. Autumn colours are also visible in some of the forests surrounding the lakes.
Given that it’s autumn here in Australia right now, the image seems vaguely appropriate.