Having white background on posts and widgets

Hello to everybody,

I am having quite a common issue with the background of text boxes (posts) and widgets.

I am using GamesPark theme, on my frontpage, the text has a light gray background which makes a huge contrast between the background behind it and the background of the page. This really bothers me. It also appears on the widget on the primary widget box on the right.

I want it to be the same as the background of the whole page (not the image background but the dark gray). Is there any solution for that?

On a second thought, I might ask you guys if you could help me doing the dark gray background transparent so users can see the image background as well, leaving the primary widget box with the dark gray background.

http://www.csgomonster.com
Thank you in advance