The mobile menu font color can be set from Theme Options -> Typography -> Navigation -> Menu 1 level, Screenshot: http://take.ms/wOdrQ After changing this, try clearing your browser cache if you didn’t see any changes.
If that didn’t work, you can add this Custom CSS in Theme Options -> Stylings -> Custom CSS for global,
.mobile-menu-wrapper .menu > li > a { color: green !important; }
