Hey JJ0007
red packet is actually fresh water, but can be used in species that crosses over to a brackish water. Such as bream, flatty, tarwine etc.
once you see “Smelt” as a flavour or variety, smelt is a fresh water bait fish so that gives you a bit if an indication
blue is only salt, by definition, but some lures like grubs or mullets can also be used in fresh water