I'm guessing you are using ossn4.0, with responsive theme.. ?
those are very "tricky", hard to explain, but i sent you a -add friend- request on here, maybe i can take a look at your site. (i wouldn't mind).

i am still working with ossn3.9, slowly, (very slowly) trying to migrate to the responsive 4.0 theme without losing my 3.9 look. it can be difficult.

anyways, you can email me also if you would like; [email protected]

thank you a lot i have fixed... sir G Kroschel and when users view site using opera min browser on mobile phone some tabs don't show like tag friends tab ,photos tab and location tab on post area<whats in your mind area> and top menu like messages,notification ,friends and setting drop down menu i would like to fix these so users will be able to view them ......ie change them to more constrated colour

if your thinking of just the center area, "wall/newsfeed", and not the background of the site itself?

I think you will have to look into finding the proper #color to edit in this file.. perhaps.

as an example;
*/components/OssnWall/plugins/default/css/wall.php

the very first section reads:

.ossn-wall-container {
width: 526px;
background: #FFF;
border: 1px solid;
border-color: #E5E6E9 #DFE0E4 #D0D1D5;
-webkit-border-radius: 3px;

}

changing the 3rd line from "backgroud #fff" (white) to "background #000" (black), for instance will make the Posting area on top Black, You will have to find the rest throughout the css file wall.php to locate the comments, etc.. and the HEX# for the color of Blue that you are looking for.

careful changing colors though, it can really change the "fluid/flow" of how the site looks overall, just my opinion.

a good site to test/check HEX# for the color you want is here:
http://www.color-hex.com/

hope this helps.
G