This is a false color image using three infrared wavelengths. The yellow-green tinge of the GRS indicates the higher extent of the cloud particles, relative to the surrounding region, and shows structure within the red spot itself.
Blue regions surrounding the red spot indicate a thinning of the clouds there.
The full set of wavelengths and observing angles will provide a comprehensive description of the cloud height distribution. This observation was made at a phase angle of 41 degrees.