I've seen this one around a bit, and wanted to try it for myself. Not much more to say about it.
This is more information, links, etc. about it here: www.spacetelescope.org/images/heic1811a/
Saturation was increased. Some very slight color shifts were made to make cyans slightly bluer, and reds, oranges, and yellows slightly less saturated. Stars were masked from saturation increase. Some stars had moved around due to time-disparate datasets and proper motion. I moved many of them to match the F555W filter.
This image was created using data from the following proposals:
Red: ACS/WFC F814W + WFC3/UVIS F665N
Green: ACS/WFC F555W
Blue: ACS/WFC F435W + WFC3/UVIS F275W + WFC3/UVIS F336W
North is 5.5° counter-clockwise from up.