Step 1: 
Knowing were to find the style sheets.
    Site style Sheet
    Page style sheet

Step 2:
     Backgrounds
        Page
            Body / Main
            Top Toolbar
            Main Navbar
            My Navbar
        Widgets
        Widgets Title bar

Step 3:
    Widgets
        Background
        Additional Styling
        Title Bar
        Placement
        Optional Styling

Step 4:
    My navbar
        Background setting
        Moving Inner menu
        Menu Classes Info

Step 5:
    Advanced option
        Hiding title bar
        Adding site images to title bar
        Hiding widgets
        Moving widgets

    You navbar has a main class ( .RadDock_menu, .RadDock_menu .rdContent ) which is its widget class and inner classes (see below).

    If you have gone over the widget section you will know how to edit the main class.
Sample:
.RadDock_menu { margin:0 0 0 0; color:#000; font-family:'ms sans serif',sans-serif; text-align:left;}
/* inner content start */
.RadDock_menu .rdContent{ background-color:white; overflow:visible; top:0px; /*brd*/ padding-bottom:0px; /*brd*/ font:11px/1.2 verdana, sans-serif;}

 

    Inner classes: More details coming soon.  Go ahead and edit the styling, I am sure you can figure out what edits what.
 .RadMenu_menu { background:gray; filter:alpha(opacity=80);-moz-opacity:.80;opacity:.80; }
.RadMenu_menu_Context { background:none; }
.RadMenu_menu .link { text-decoration:none; color: white; line-height: 20px; }
.RadMenu_menu .link .text { padding-right: 20px; cursor:pointer; }
.RadMenu_menu .link:hover,
.RadMenu_menu .focused,
.RadMenu_menu .expanded
{ background:black; border-bottom:none; border-top:none; color: white; }
.RadMenu_menu .link:hover .text,
.RadMenu_menu .focused .text,
.RadMenu_menu .expanded .text
{ border-top: 1px solid #1B2B84; }
.RadMenu_menu .rootGroup .disabled:hover { border-bottom:none; border-top:none; }
.RadMenu_menu .rootGroup .disabled:hover .text { border-top: 1px solid #a7cfe8; }
.RadMenu_menu .text { padding: 0px 15px; font-size: 11px; }
.RadMenu_menu .group { background: #15572A; border: 0px; }
.RadMenu_menu .group .link { background: #15572A; border: solid 1px #bfcde3; border-top-color: #15572A; text-align: left; padding-right: 0px; }
.RadMenu_menu .group .text { padding-left:6px; padding-right: 40px; }
.RadMenu_menu .group .link:hover,
.RadMenu_menu .group .focused,
.RadMenu_menu .group .expanded
{ background: #759580; border-bottom: 1px solid #15572A; border-top: 1px solid white; font-weight: normal; }
.RadMenu_menu .group .link:hover .text,
.RadMenu_menu .group .focused .text,
.RadMenu_menu .group .expanded .text
{ border-top: 0; }
.RadMenu_menu .leftArrow,
.RadMenu_menu .rightArrow,
.RadMenu_menu .topArrow,
.RadMenu_menu .bottomArrow,
.RadMenu_menu .leftArrowDisabled,
.RadMenu_menu .rightArrowDisabled,
.RadMenu_menu .topArrowDisabled,
.RadMenu_menu .bottomArrowDisabled
{ border-left: 1px solid #bfcde3; border-right: 1px solid #bfcde3; background: #a7cfe8 url('/_static/themes/perkasie/menu/img/left.gif') center center no-repeat; width:15px; }
.RadMenu_menu .topArrow,
.RadMenu_menu .topArrowDisabled
{ background-image:url('/_static/themes/perkasie/menu/img/top.gif'); width: 100%; }
.RadMenu_menu .bottomArrow,
.RadMenu_menu .bottomArrowDisabled
{ background-image:url('/_static/themes/perkasie/menu/img/bottom.gif'); width: 100%;}
.RadMenu_menu .rightArrow,
.RadMenu_menu .leftArrow
{ height:100%; }
.RadMenu_menu .rightArrow,
.RadMenu_menu .rightArrowDisabled
{ background-image:url('/_static/themes/perkasie/menu/img/right.gif'); }
.RadMenu_menu .vertical .separator .text { background: #d4e5eb; font-size:1px; padding-top: 2px; border-left: solid 1px #bfcde3; border-right: solid 1px #bfcde3; }
.RadMenu_menu .expandLeft,
.RadMenu_menu .expandRight
{ background:transparent url(/_static/themes/perkasie/menu/img/groupImage.gif) right center no-repeat; margin: 0px; }
.RadMenu_menu_rtl .group .link:hover .expandLeft,
.RadMenu_menu_rtl .group .link:hover .expandRight
{ background:transparent url(/_static/themes/perkasie/menu/img/left.gif) left center no-repeat; margin: 0px 1px; padding-left: 8px;}
.RadMenu_menu_rtl .expandLeft,
.RadMenu_menu_rtl .expandRight
{ background:transparent url(/_static/themes/perkasie/menu/img/groupImageRTL.gif) left center no-repeat; }
.RadMenu_menu .link:hover .expandLeft,
.RadMenu_menu .link:hover .expandRight,
.RadMenu_menu .focused .expandLeft,
.RadMenu_menu .focused .expandRight,
.RadMenu_menu .expanded .expandLeft,
.RadMenu_menu .expanded .expandRight
{ background:transparent url(/_static/themes/perkasie/menu/img/invertedGroupImage.gif) right center no-repeat; }