Actually, I know what you're talking about:
The prize plugs during the course are shot previously (obviously). At the time they shot the plug with Robin and/or Jamie, the logo was not painted on the podium yet, and it was still purple from previously on the Super Sloppy version.
On the other episodes from the 1990 season when they have the 4 number score displays (which is every episode of the season except 4), the logo has a red outline, and the Family Double Dare logos on the players podiums are dark green. While they were previously light green, in prize plugs you can see on some of them that they are light green, proving they are taped previously.
Hope that helps!
Adam