Hi there,
try this CSS:
/* Add Background Color for highlight */
.main-navigation .main-nav li.highlight a {
background-color: #3A858E;
}
/* Add this if you want to change the color on hover */
.main-navigation .main-nav li.highlight:hover a {
background-color: #3A858E;
}
or for text colors
/* Add label Color for highlight */
.main-navigation .main-nav li.highlight a {
color: #3A858E;
}
/* Add this if you want to change the color on hover */
.main-navigation .main-nav li.highlight:hover a {
color: #3A858E;
}