The Hubble images were created from HST data from proposal 11956: K. Noll, Z. Levay, M. Mutchler, L. Frattare, M. Livio, W. Januszewski, C. Christian, F. Hamilton, and H. Bond (Hubble Heritage Team/STScI).
F450W (B), F606W (V), and F814W (I)
The image is a composite of separate exposures made by the WFPC2 instrument on the Hubble Space Telescope. Three filters were used to sample broad wavelength ranges. The color results from assigning different hues (colors) to each monochromatic image. In this case, the assigned colors are:
Blue: F450W (B)
Green: F606W (V)
Red: F814W (I)