The image was created from Hubble data from proposals 10824 and 11782: O. Gnedin (University of Michigan, Ann Arbor), A. Gould, J.L. Prieto, and K. Stanek (Ohio State University), J. Anderson, H. Bond, M. Livio, E. Nelan (STScI), and W. Brown, M. Geller, S. Kenyon, and M. Kurtz (Harvard-Smithsonian Center for Astrophysics).
This image was originally black and white and recorded only overall brightness. These brightness values were translated into a range of bluish hues. Such color "maps" can be useful in helping to distinguish subtly varying brightness in an image.