This image of Jupiter's Great Red Spot has different colors than what you
normally see. This is because it was recorded by an instrument that looks at
infrared 'light' (rather than visible), the Near Infrared Mapping
Spectrometer (NIMS) in late June, 1996. Red, green, and blue colors were
chosen to represent what the NIMS 'eye' saw at three different infrared
wavelengths, which were picked because they reveal the differences in
Jupiter's cloud heights. The yellow-green tinge of the Great Red Spot
indicates the cloud particles are higher relative to the surrounding region,
and shows structure within the red spot itself. The blue regions indicate a
thinning of the clouds there.

The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's
Office of Space Science, Washington, DC.