Chemical film development has to deal with a lot of things like
- different film stock
- different chemicals
- different times and temperatures
- etc.
Change one and the result looks different.
Whether the orange mask is pink, orange, brown etc. doesn’t matter that much when converting with NLP. Simply white balance from an unexposed part and NLP will handle the rest. Nevertheless, conversions might look different, but that has other causes too. I’ve put some of it in here: What to Expect From Negative Lab Pro