https://e621.net/wiki/show/tiger

Tigeress, black_tiger, golden_tabby_tiger, snow_tiger, golden_tiger, maltese_tiger, and white_tiger are set to be aliased to tiger rather than it merely implying it.

Therefor these tags are interchangeable with each other and the tiger tag when they really shouldn't be. I have no idea how to fix this myself. I guess that's what this forum is for, though.

They were aliased because they're not separate species of tiger or anything, they're all just terms for the tiger. They're not a species, they're all terms or tiger.

Tigress is an unnecessarily gendered term for tiger. We alias all of those to the base species tag. Bull, for example, aliases to cattle and lioness aliases to lion.

The others are just different fur color variants of the tiger, often caused by lack of or excess melanin, such as albinism/leucism and melanism. You can search for things like black tiger with searches like melanism tiger for example.