Well the hues won't only be seen on veterans, since probably some folks will purchase the tubs then spend the uses on dyeing things that they'll sell, or eventually give away, or etc. There's nothing we can really do (well, not within a reasonable amount of coding work anyway) to make it so the hues literally cannot dye anything except the possessions of the veteran who got the tub - or would unhue if traded, etc. It'd just be a silly thing to spend time trying to do I think. So, likely you'll eventually see these hues on stuff that doesn't belong to the vet who purchased the tub in the first place.
Gaara, they're pretty different but it's difficult to show that without putting together a screenshot of 50 different types of items/mobs dyed with it.
I mean, they're similar in the way that "there are other hues with a bright red cast", but the overall look, especially when animated, is very different than anything we already have. When I created the new patch hues I spent a lot of time making sure they were different than what we already had in terms of the hue palette used to create each hue. Some are similar - there's a sorta olive green already that's used for slimes, but when I made an olive color, I aimed for looking like an actual green olive and so it's more deep and with more yellow/brown than the pre-existing hue. Likely a number of folks will consider the existing hues "good enough" of a match and not want to purchase the tubs, which is completely fine. But I think a fair number will want these hues once they can see them in action