Color of the extra area on side

should be able to do that using the wp-admin->customizer->color->background color.

Richie, when I change color in wp-admin->customizer->color->background color, all area in the blog was changed, and not only that extra area in both sides… the same happens when I choose a background image for the site.

What I need is change the color of only extra area, not in the content area (in center of site).

??

that’s odd, if changing the background color or image, the bodycontent should in white, not transparent and overlay with the bg color.
did you have custom css added like ‘##bodywrap #bodycontent { background: transparent; }’? that might affected this.

any live site so i could check the source code.

the theme will automatically change the layout to box style if any bg color or image saved in wp-admin->customizer but in your case it did not so might be something causing this in your end.

Yeah, I have the site https://www.nosblogamos.com.br but in other times you can’t open it (I don’t know why this happens) … this is what has in the Custom CSS field:

#siteinfo { width:100%;float:left;overflow:hidden; }
#siteinfo img { max-width:100%;height:auto;float:left; }

#custom #top-navigation li a { font-size:10px; color:#ffffff; }

#custom #top-navigation .sf-menu a { padding:1em 3em; }

#custom #main-navigation li a { font-size:15.4px; }

.sf-menu ul li a {
font-size: 1.2em !important;
}

#custom #right-sidebar ul.recent-postcat li {
padding: 0 0 7px !important;
margin: 0 0 7px !important;
}

#custom .footer-top {background-color: #cccccc;}
#custom .footer-top .widget li { font-size:10px; }
#custom .footer-top .widget li,#custom .footer-top .widget div,.footer-top .widget a { color:#000000; }

#custom .fbottom, #custom .fbottom a {
color: #ffffff;
}

#custom #post-entry div.post-thumb img {
border: 1px solid #ccc;
padding: 5px;
max-width: 95%;
}

#post-entry div.post-thumb.in-archive {
width: 300px;
height: 225px;

}

#post-entry article .post-right {
margin: 0 0 0 140px;
}

.feat-meta {
display:none;
}

#custom .post-comment, #custom .feat_comment {display:none !important;}

#custom #commentpost h4 {
margin: 0 0px 0.55em !important;
}

.wpp-list li {
float: none;
clear: left;
margin-bottom: 15px!important; /*NEW*/
}

the custom css didn’t have anything that might cause the bug.
try resave (not just preview) background color via customizer. and clear cache etc afterward.
refresh the site again.