I've found an article from 2012 detailing a bug where Helvetica Neue is rendered as white with a black outline: https://support.mozilla.org/nl/questions/929862 I'm not sure how this bug suddenly appeared here on my Firefox in 2015 but it immediately started happing after installing the Windows 10 upgrade (from Windows 8.1). It seems like the browser selects "Helvetica Neue 75 Bold Outline" instead of the normal "Helvetica Neue 75 Bold". There's nothing wrong with the font itself, I can use any variation of HN without problem in Photoshop or other applications. The article I posted links to a page explaining how to force Firefox to use a different font instead of Helvetica, but that isn't an option for me. I'm a web designer, my browser needs to function properly.