You can add these CSS blocks to your Thesis -> Custom CSS screen

CSS

1. Widen blog / posting page after removing share / comment / dates boxes.

First remove the side boxes by going to Thesis Skin Content -> and click the "Post/Page Output" button. Uncheck Date, Number of Comments and jQuery share count / button and click Ok and add the below to your Custom CSS:

#content .type-post.entry, .search #content .post_box.entry, #content .type-attachment.entry {
    padding-left: 0px;
}

.post-meta {
    display: none;
}

2. Change menu colors

/* Change menu background color */
.menu-primary {
    background: #000;
}

/* Change main menu text / border colors */
.menu-primary a {
    border-left: 1px solid #E3E3E3;
    color: #FFF;
}

/* Change menu text highlight color */
.menu-primary li a:hover, .menu-primary li a:hover, .menu-primary li li a:hover, .menu-primary .current-menu-item > a {
    color: #FFF;
}

/* Change submenu colors */
.menu-primary li li a {
    background-color: #000;
    border-color: -moz-use-text-color #E3E3E3 #E3E3E3;
    border-right: 1px solid #E3E3E3;
    color: #FFF;
}

3. Reverse the postion of the logo & menu

.sidebar-content #sidebar, #title-area, .content-sidebar #content {
    float: right;
}

#header .menu-primary {
    float: left;
}
.mobile-menu {
    position: relative;
}

4. Change social icons colors

.featured_box .social_list a {
    color: #fff;
}

.featured_box .social_list a:hover {
    color: #fff; 
    background: #000;
}

5. Adjust Content / Sidebar widths

.sidebar {width: 30.5556%;}
.content-sidebar #content, .sidebar-content #content {width: 65.2778%}

6. Add background color behind menu area

.wrapper-sticky, #header {background: #000;}

7. Change background color behind single post titles from black to white

/* Note the RGBA color value is necessary as well, search "HEX to RGBA color conversion" in Google for many conversion sites if you don't know how to find RGBA colors .75 refers to the opacity of the background (1 is solid) */
#featured_post_image .entry-title {
    background: #fff;
    background: rgba(255,255,255,.75);
    color: #000;
}

8. Change text color in background slideshow area

#featured .content h2, #featured .content p {
    color: #ffffff ! important;
}