The image was created from Hubble data from proposals 10802 and 11570: A. Riess (STScI) et al.; 9788: L. Ho (Carniegie Institute of Washington) et al.; and 8100: A. Saha (NOAO/AURA) et al.
F555W (V), F658N (H-alpha+[N II]), and F814W (I)
The image is a composite of separate exposures made by the WFPC2, ACS, and WFC3 instruments on the Hubble Space Telescope. Three filters were used to sample broad and narrow wavelength ranges. The color results from assigning different hues (colors) to each monochromatic image. In this case, the assigned colors are:
Blue/cyan: F555W (V)
Red: F658N (H-alpha+[N II])
Red/yellow: F814W (I)