Event Calendar RSVP “Can’t Go” button hover color

We use Event Calendar (free version) with the Event Tickets add-on. We need the “can’t go” button to appear on events.

When we’ve selected “can’t go” to show up in the event setup and then publish the event, we can only see the “can’t go” button if we hover over it. For our users, it’s completely invisible because they don’t know to hover on it in order to find it so it’s useless to us. We need to change the background color of the “can’t go” button.

I’ve searched these forums for CSS to add to change the background color of the “can’t go” button but can’t find it. I have used the themers guide in the past to help me figure out CSS code to customize the site, but I can’t find it now (page has a 404 error). This situation impacts all events on our calendar.

Our page is member-only to protect our Scouts so I’m not sure how to give anyone access to see it without you joining the site. I’m open to allowing one person to do so to help me with the CSS.

The page I need help with: [log in to see the link]