I wonder when someone first pointed out the parallel of "same color, but with orange trim" for John/TJ teasing?
Eden's reaction, on the other hand, would probably be something like this:
"An odd coincidence, to be sure, but my parents represent only a single data point. If John and Tessa never become romantically involved, then Mother and Father remain a statistical outlier. Only if they begin dating will the similar color choices be considered relevant for future data sets."
Probably pretty accurate.
Janine noticed it immediately at the end of "Eye of Aretpo", though now we know she already knew about TJ's uniform choice--thus her note of amusement ("an enigmatic smile") at the end of "Born to the Purple" Heck, considering that this case was a complete coincidence, and Janine's uniform choice was almost certainly a deliberate parallel to Egon's, Janine would argue that this is an even bigger
I guess Marie Lupin almost certainly was the first one to actually make jokes about it; I guess by the time the next story takes place it's a year later so she's stopped picking at that scab. For the most part.