Mac users, who’ve upgraded to Snow Leopard, may’ve notice, that your CSS colors & your untagged/unmanaged images look darker on Snow Leopard than on previous versions of Mac OS. You'll also see less of a visible color shift when going from Photoshop to Flash or other unmanaged environments (e.g. Internet Explorer). Its becuase, Apple has switched to a default gamma of 2.2, which’s what Windows has used for years. Colors that aren't color-managed’re going to look darker on the whole. Your whole display’ll now be closer to what Windows users see “For what it's worth, when I was a Web designer I'd always set my Mac monitor to gamma 2.2, the better to match the darker Windows environments on which my designs were most often viewed.”reports Adobe.