Answers for "in select2 how to select all"

select2

<link href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/select2.min.css" rel="stylesheet" />
<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/js/select2.min.js"></script>

select2 .select2-results .select2-highlighted

#menuOption1-container  .select2-results__option--highlighted {
    background-color: #50831F !important;
}

#menuOption2-container  .select2-results__option--highlighted {
   background-color: #28915F !important;
}