Problem is that the first part talks about yellow barrels. If you count them all, even the dirty ones, it's 6, not 3. Seven is in a different area, not the sellers area.
I can see your point as it toke me a while to figure it out however the barrels were pretty easy to see which ones were the first code, making the code not so hard to see. The only one I got stuck on was the second one, I just went up from zero as I knew all the other codes so it wasn’t hard I just didn’t think it was in the right area, although the note does say it’s in the starting area so who knows -_😑_-