You really don't want to know how long it took a guy to get this picture. He did everything but take a picture for about 25 minutes. Look thru the camera, play with the light meter. Look thru the camera again, Gee, did I load film? Look thru the camera again, and again... and again.... By the time he took the picture a lot of crowd were not even looking at him anymore. Check the inset pic.
You are correct - kid sizes were yellow and adults blue. Of course that meant that some larger kids were walking around in blue and some adults (those who were very small sizes) were in yellow.