So I have Bacopa Araguaia because its leaf are purple(when I bought this plant its name was: 'Bacopa sp Purple')Bacopa araguaia is more of a purple color
"Bacopa araguaia" isn't a valid species name. If it were, it would be something like "araguaiensis". There are also no records of a species with that name. I think that in that other thread, you've got two species with similar or the same trade name that may be from the same general area. That's not unheard of. I suspect the purple one is what's known as 'colorata' but doctored up or with funny color balance, etc. Either that, or it's something new with really, really weird coloration.