I thought in the episode when they went to the park to play after church either Kate or Jon said they were all dressed in red so it would be easier to find them all. And I thought that in this last episode there was a comment about how easy it was to find them dressed in the yellow. I wonder though how long before they decide they don't want to be dressed alike anymore.
I'm sure they'll be dressed alike on TV as long as Gymboree sends them free clothes.