Hi Judy,
Currently we don’t have customizer setting for changing the active font colors in the menu.
But you can do it by going to style.css file line no.2353 and change
.site-navigation .current-menu-item > a,
.site-navigation .current-menu-ancestor > a {
background-color: #080d07;
color: #080d07!important;
}
Remove the color code with the code you wanted.
Thanks.