User blog:Seadrus/Customizing page?

In this:

body.mediawiki { background-image: url("http://2.bp.blogspot.com/-e5OiZNTMM7s/T2HQ2qu-g7I/AAAAAAAABMk/HoVDOqbFuT8/s1600/Seamless+marble+texture+%252811%2529.jpg"); } What would be the parameter for the page opacity be? I am so confused.  Seadrus's User Page  Talk Page  22:26, October 27, 2013 (UTC)