Gold Band fan, here.
I usually use the generic, less-powerful knockoffs due to cost.
But, if I go on travel and space/mass is at a premium, I spring for the real Yellow deal for the 'boys.
I have never used Green or Blue, but next trip I will "go Green" in the name of science. And my 'boys.
Also, keep some in the gym locker. Helps when you are doing shrugs (increases grip, like chalk) and if your anti-persperant ever dies (breaks to bits or something), GB will square you away.
Why use Gold Bond? Well, if you have ever performed outside manual labor in the SE USA or other places with high temps & humidity, you will understand that you can start sweating at 0630 and not quit until you hit the showers at 1830. You never really dry out, you are just varying degrees of hot & sweaty. GB, along with loose clothing and going commando, help avoid heat rash/crotch rot/swamp nuts/whatever.
Heat rash "down south" can be debilitating. I know from experience.
GB not only prevents heat rash, it can make a case of heat rash more bearable. The initial hit of GB on heat rash is like boiling Icy Hot and is, uh, "bracing." But, it simmers down after a few minutes.
Trust me- If you have ever seen what happens when the moisture and humidity are NOT taken care of, it is not pretty...
That is why most of us wore no underwear during Vietnam- Anything to stay cooler and drier.
That injury can be so debilitating it will take soldiers out of the field and into the hospital, much less the average child or adult back here.