It is this CSS:
body.custom-background {
background-color: #000000;
background-image: url('http://www.decomachine.net/wp-content/uploads/2013/08/header11.jpg');
background-repeat: no-repeat;
background-position: top center;
background-attachment: fixed; }
And this one:
#bg_image { display:block;margin:0 auto;} #main, #access ul li.current_page_item, #access ul li.current-menu-item ,#access ul ul li { background-color:#000000} #access ul li { background-color:#000000} #primary { background-color:#000000} #secondary { background-color:#000000} * , .widget-title {font-family:Arial Black, Gadget, sans-serif ; } #content h1.entry-title a, #content h2.entry-title a, #content h1.entry-title , #content h2.entry-title {font-family:Arial Black, Gadget, sans-serif ; } .widget-area * {font-family:Arial Black, Gadget, sans-serif ; } .entry-content h1, .entry-content h2, .entry-content h3, .entry-content h4, .entry-content h5, .entry-content h6 {font-family:Arial Black, Gadget, sans-serif ; } #content .wp-caption { background-color:#000;color:#CCC;}
#access ul li { border-radius:0;-moz-border-radius:0;border-radius:0;} .entry-meta { background:#FFF;} .entry-content ul li { background-image:none ; padding-left:0;} .entry-content ul { margin-left:0;} #respond .form-allowed-tags { display:none;} .nocomments, .nocomments2 {display:none;} .comments-link span { display:none;} #content table {border:none;} #content tr {background:none;} #content table {border:none;} #content tr th,
#content thead th {background:none;} #content tr td {border:none;} #header-container > div { margin-top:9000px;} body { background-color:#000000 !important ;} #header { background-color: ;} #footer { background-color:#000000 ;} #footer2 { background-color:#000000 ;} #site-title span a { color:#fffff ;} #site-description { color:#999999 ;} #content p, #content ul, #content ol { color:#ffffff ;} .widget-area a:link, .widget-area a:visited, a:link, a:visited ,#searchform #s:hover , #container #s:hover, #access a:hover, #wp-calendar tbody td a , #site-info a ,#site-copyright a, #access li:hover > a, #access ul ul :hover > a { color:#0D85CC;} a:hover, .entry-meta a:hover, .entry-utility a:hover , .widget-area a:hover { color:#12a7ff ;} #content .entry-title a, #content .entry-title, #content h1, #content h2, #content h3, #content h4, #content h5, #content h6{ color:#000000 ;} #content .entry-title a:hover { color:#000000 ;} .widget-title,#footer-widget-area .widget-title { background-color:#000000 ;} .widget-title { color:#2EA5FD ;} #content article.post{float:left;width:47%;margin-right:3%; } #content article.sticky { margin-right:3%;padding:0; } #content article:nth-of-type(2n+1) {clear: both;} #footer-widget-area .widget-title { color:#0C85CD ; ;} #footer-widget-area a { color:#666666 ;} #footer-widget-area a:hover { color:#888888 ;} #content .wp-caption { background-image:url(http://www.decomachine.net/wp-content/themes/mantra/images/pins/mantra_dot.png) ;} .widget-area ul ul li{ background-image:url(http://www.decomachine.net/wp-content/themes/mantra/images/bullets/mantra_dot2.png);background-position: 0px 8px ;} .page h1.entry-title, .home .page h2.entry-title { display:none;} h1.page-title { display:none;} .entry-meta .bl_sep {display:none;} .entry-meta span.entry-date,.entry-meta span.onDate {display:none;} .entry-meta .comments-link,.entry-meta2 .comments-link{display:none;} .entry-meta .author {display:none;} .entry-meta span.bl_categ {display:none;} .entry-utility span.bl_posted, .entry-meta2 span.bl_tagg,.entry-meta3 span.bl_tagg {display:none;} .entry-utility span.bl_bookmark {display:none;} .entry-meta .entry-time {display:none;} #content .entry-meta {display:none;}
#branding { height:900px ;}
Whew – not gonna rewrite that also for clarity, but all the above requires editing the background color.
To discover what CSS is output by your theme, use a web inspection tool such as Firebug: http://getfirebug.com/ , Chrome Inspect Element: https://developers.google.com/chrome-developer-tools/ or Internet Explorer 9+ F12 Dev. Tools: http://msdn.microsoft.com/en-us/library/dd565627(v=vs.85).aspx#csstool
There are others.
When editing CSS, use a Child Theme
http://codex.wordpress.org/Child_Themes
Custom CSS Plugin, or Theme provided custom CSS option.
Edits to parent themes are lost on theme update.
Learn CSS: http://www.w3schools.com/css/