Good evening Marc and welcome to the Events Calendar forum!
Thank you for reaching out to us.
I would love to help you with this topic.
You are right, this is broken at the moment of writing.
We apologize for the inconvenience caused by this glitch.
We are actively working on a solution for this.
Alas, I cannot guarantee when it will be fixed, as it’s in the development team’s hands now.
They need to assign it, code it, test it, and schedule it for release.
The good news is that you will be contacted as soon as a fix is available.
Thank you for your patience as we see this through.
In the meantime, we do have a CSS workaround that you can use.
Read all about it here: https://theeventscalendar.com/support/forums/topic/featured-event-color-will-not-change-after-update/
Best regards,
Geoff B.