Hello @revolution,
Great question! While I have not come across an answer for this myself, I bet you could accomplish it using the tribe_events_has_soldout function:
https://theeventscalendar.com/function/tribe_events_has_soldout/
It would likely be something where you wrap the page title in that function and, based on the output, specifying a classname to create the effect.
For demonstration purposes:
<?php if tribe_events_has_soldout() {
the_title( '<h1 class="tribe-events-single-event-title-soldout">', '</h1>' );
} else {
the_title( '<h1 class="tribe-events-single-event-title">', '</h1>' );
} ?>
I haven’t tested this at all, but I’m hoping it gives you something to play with. You can see how adding a new classname of tribe-events-single-event-title-soldout would then allow you to write CSS in your theme’s style.css file to modify the appearance of the title.
Cheers!
Geoff