CK Photo,
The gray borders can be removed by changing the following colors to #FFFFFF.
For the gray line underneath the menu:
1. Line 183 in style.css
#page {
background: none repeat scroll 0 0 #CCCCCC;
border-radius: 5px 5px 5px 5px;
For the three lines at the bottom of the page:
2. Line 2414 in style.css - Change border-bottom and border-top to #FFFFFF (two of the lines should be fixed by this)
#site-generator {
background-color: #FFFFFF;
border-bottom: 2px solid #AAAAAA;
border-radius: 0 0 5px 5px;
border-top: 1px solid #CCCCCC;
clear: both;
color: #666666;
display: block;
font-size: 12px;
line-height: 2.2em;
3. Line 743 in style.css - Change border-bottom to #FFFFFF
.hentry, .no-results, #author-info, #disqus_thread, #content .error404 {
background-color: #FFFFFF;
border-bottom: 2px solid #CCCCCC;
border-radius: 5px 5px 5px 5px;
margin: 0 0 2em;
padding: 0.5em 5% 2em;
position: relative;
width: auto;
* The lines numbers could be different, but you should be able to find the relevant code by searching. See if that works.