Option Set Not Available Color

Hello! It looks like by default these are a light grey when there is no option available (in this case because the quantity is 0).

How would I override this grey color for something else, as I feel it’s not obvious enough to the user that it’s grey/not selectable. Thanks!


I believe this actually defaults to the browser - so different browsers will have a slightly different display for elements like this

If you can leave a read only link I can see if it can be modified with CSS