Do the pictures turn purple immediately, or does it take some minutes?

If they turn greypinkpurple-ish over a few minutes, then I suspect the fixer. Is it the same colour as if you take an unexposed and undeveloped paper out in daylight? Greypinkpurple-ish is a very good description of what happens to them.

And as a last comment: Your English is fine, so do not worry. What other language(s) do you know? I am convinced that someone here understands just about any language!