When I shopped my Torpedo Alley, I didn't pay attention to where all the different colored posts came from, figuring I would just refer to online photos later on.
When doing this, it seemed to me that DE went a little overboard with the whole Green - Blue - Yellow deal around the playfield. I get that it relates to target zones and ships and such... but apparently using each color in the target banks, and S-U-B lanes, and pop caps was not enough: they tried to "alternate" these areas come hell or low water (sub pun, boo) all over the pf and it just doesn't work IMHO. The color balance is too schizophrenic!
So when I reassembled mine I made a few small changes:
1) According the majority of pics it seems the factory put green posts in the left sling area, and yellow in the right. I swapped the green for more yellow ones (I don't remember which part of the game they came from). The yellow posts just make sense here since they coordinate with the uniform sleeves and medals art in this part of the pf.
2) That leaves all the blue and green posts for the oceanic part, which again makes the most sense. To that end, I put most of the green posts on the left side of the pf where the green targets and left/green pop and inlane guides are. Likewise, I concentrated the blue posts to the center and right of the pf.
3) I swapped the stock locations of the blue and yellow pop caps. With a yellow cap over the yellow "Laser Kick" target, flanked by yellow post sleeves, this area of the pf has a more unified look. And being all yellow is appropriate because that stupid target is a dangerous shot!
The best part is you don't have to buy any additional posts of Color X: the appropriate quantities all seem to luckily match, only the locations change. So it's 100% reversible for any "purist" collectors out there.
It's not a huge change, but it's a big improvement in making the art and color presentation more cohesive IMO.