cairnslifestyle,
Since you’ve indeed confirmed that this is an issue specific to your theme, we’re unfortunately able to help here. I would suggest reaching out to the developer of your theme to see if they can offer some guidance. You might also take a look at this article, that explains how to change/preview CSS styling in the Google Chrome developer tools.
With that being said, you could probably do something like this for the title field:
.events-community-post-title input {
border: 1px solid gray;
}
Thanks! 🙂
-Casey-