Full credit goes to Code Monkey on YouTube for pointing this out in a Shorts video!
Edit > Preferences > Colors, then under Scene, you can change the background color to anything you’d like. I was having trouble lining up my roads in the Scene window against the default dark background while working on the Delivery lessons, so I changed it to a bright purple-pink for contrast, and it’s now extremely easy to tell where a road segment doesn’t meet up properly.
I told a seasoned veteran game dev about this, and they didn’t know about it either, so I thought I’d share the knowledge in case it helps anyone else here! <3