https://marco.org/2009/06/16/one-unexpected-disadvantage-to-using-safari
One unexpected disadvantage to using Safari instead of Firefox as my default browser: most of the core icons in my Dock are now blue, making them more difficult to quickly and automatically distinguish without slowing down for a closer look. Firefox’s big orange icon was much easier to spot almost instinctively.
At least I have my trusty Butters Bear Adium icon, in use since 2004, to break up the blue a bit.