This composite image combines Extreme Ultravoilet Imaging Telescope (EIT) images from three wavelengths (171, 195 and 284 angstrom) into one that reveals solar features unique to each wavelength. Since the EIT images come to us from the spacecraft in black and white, they are color coded for easy identification. For this image, the nearly simultaneous images from May 1998 were each given a color code (red, yellow and blue) and merged into one.
SOHO is a project of international cooperation between ESA and NASA. See the SOHO web page at http://sohowww.nascom.nasa.gov/ for more details.