To whom this may concern,
I downloaded the UCSF Chimera 1.4.1 update for Mac OS X and noticed that the Chimera symbol had a grey outline around it, likely due to multiple alpha channels in rendering the image into .ICNS format, so I recomposed the image in higher quality and it is attached below. Also below is an accompanying symbol for MS Windows format (.ICO). These icons are free of charge, keep up the good work.
Jessen Bredeson
Fourth-Year
Genetics, Genomics & Development
Molecular and Cellular Biology
University of California, Berkeley