[tbworld]

What I have surmised from your post, try the following:

.userprof_editor { 
    border-width: 1px 0px 0px; 
    border-style: solid;
    border-color: #2E3539; 
}

Above code: Leaves the border in the original post and changes the border color to your desired #2E3539.

The problem assumably was due to the boarder being enabled in an associated class, using an inherited color -- it is only a guess. I would need a link to your page to be sure.