That indicates that you have Auto-Ripple turned on. A couple of years ago, this was a highly requested feature to highlight that Ripple was 'on'. Beforehand and without such red highlighting, timelines could be totally stuffed up by Ripple unknowingly being activated when making an otherwise simple timeline edit.
To get rid of the red cursor and red framing on the event, turn Rippling off.
I've not seen that the Ripple highlight color can be changed, but red is the obvious color as conveying a 'warning'.
First, you can turn off the color change of the cursor and selection background for auto-ripple mode via the preferences dialog...in the Editing tab. (Third option from the bottom.)
Second, previously we did have an option to reverse the background colors for the events on the track, but with the new UI changes in VP 23, this option had to be dropped. It is something we may be able to add back in the future. Sorry about that.