I need to overwrite a css style that is placed in the body of my blog. See the picture:

Through the following code:
html,body{
background:#0a0a0a url(http://static.boo-box.com/campaigns/youtube-music-box-n0210-3110-cpm-bg_20131007/bg_booboxrosbg1280x1024-1.jpg) no-repeat fixed top center !important;
}
The background color of the original blog is:

I've tried to overwrite jquery, css, but nothing worked. Anyone any suggestions? Below is the code I tried, but none worked.
<style>
html,body{
background:#F1F1F1 !important;
}
</style>
$('body').removeAttr('background');
To see the problem online access: www.obovio.com.br