They usually say if they are compatible with any make and model. Unless you bought the GM stuff I think.
Typically they are not mixable unless you have the new stuff that is compatible with all makes and models which most of the new stuff is.
I would not use it in a high end vehicle that call for some special blue or pink stuff.
If you want to use what you have and are worried about it just flush the whole system and use whatever you want.
I have read to use the green over the orange and I have seen what the orange stuff can do in certain situations, not sure if the new stuff has that issue or not.
But the orange stuff is supposed to go longer between flushes.
So what vehicle are you working on?