Solved How to modify background color in user popup

.layout#kunena .dropdown-menu {
    color: #000;
}
.layout#kunena .navbar-inner {
    border-color: #000;
    background: #474747;
    background: -moz-linear-gradient(top,  #474747 0%, #000000 100%);
    background: -webkit-linear-gradient(top,  #474747 0%,#000000 100%);
    background: linear-gradient(to bottom,  #474747 0%,#000000 100%);
    filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#474747', endColorstr='#000000',GradientType=0 );
}
.navbar .nav li.dropdown.open > .dropdown-toggle, 
.navbar .nav li.dropdown.active > .dropdown-toggle, 
.navbar .nav li.dropdown.open.active > .dropdown-toggle,
.navbar .nav > li > a {
    background-color: #000;
    text-shadow: none;
}