How do I change the font of a single option in a select2

I am using select2 drop down. Some of the options are disabled and I would like to change the font of the disabled options. How do I do that in select 2? Where do I specify the class for those options?

Disabled items in a Select2 look like this: <li class="select2-results__option" id="select2-td9s-result-68sf-two" role="option" aria-disabled="true" data-select2-id="select2-td9s-result-68sf-two">Second (disabled)</li>

Select2’s own CSS uses this rule to style disabled items:

.select2-container--default .select2-results__option[aria-disabled=true] {
  color: #999;

So you could override that with a CSS rule like the following:

.select2-container--default li.select2-results__option[aria-disabled=true] {
    /* your styles here */

The rule I proposed has higher specificity than the Select2 CSS rule, so it should take precedence.