color of separator in menu

i think you have a small border?
can you try this in quick css ( and if you like you can have 2px for better seeing the effect)

.av_seperator_small_border .av-main-nav > li > a > .avia-menu-text {
    border-left-width: 2px;
    border-color: #900;
}

if you only want to have it for non transparency header state:

.header_color:not(.av_header_transparency) span.avia-menu-text {
    border-color: #900;
    border-left-width: 2px !important;
}

if you like to influence the transparency state:

.header_color.av_header_transparency span.avia-menu-text {
    border-color: #009;
    border-left-width: 2px !important;
}