I am talking about the single shot from 0:50-1:01 in this clip: https://youtu.be/YWFHeDcVNiw

Everything before that is shot in black and white/sepia. At 0:50, it's in color, but the inside of the house is painted sepia. Her extra opens the door dressed in sepia and leaves the frame. Then Garland walks through the door in color. The camera doesn't cut until the reverse angle at 1:01.

Edit: Now I realize you're just saying Judy opens the door and her double steps out. That could be. My point is that the very first shot with color out the door was shot practically. It's not two shots spliced together or color added or subtracted in post-production. They made the transition from sepia to color with some tricks while they were filming.

In the original movie, when Dorothy first opens the door and sees everything in color, the whole shot is done on color film. They painted everything inside the house to match how it looked on black and white film so the camera can slowly move through the doorway and reveal the colors.

Even Dorothy transitions to color in this scene. Her double crosses in front of the camera in a black and white gingham dress, and then Judy Garland steps out of the house in her iconic blue dress.

Edit: could be Judy in sepia and her double stepping out in color. The point is that they filmed it that way. It's not a trick they did in post-production.

I think OP meant "watershed", but their idioms were lost in an entropic waste sludge.

I was at a friend's apartment that New Year's Eve. Shortly before midnight, we went out on the balcony. This was one of those apartment complexes where there were three identical buildings around the parking lot. So probably half the balconies had people outside yelling and cheering. We all started counting down together and cheering after midnight.

Then people started going back inside. As it quieted down, I noticed that the fourth side of the rectangle formed by the three apartment buildings was the interstate highway. There were cars driving on it. There had been cars the entire time we were out on the balcony.

Personally, I don't think New Year's Eve is a big deal anymore. But I still can't imagine why so many people were out driving at midnight when the most significant digit in the year was rolling over. I can imagine reasons why one or two people might be out, but this was comparable to midnight traffic any other night of the year.