Color neutrality in filters improved dramatically nowadays, and while nobody is probably 100% neutral we are very lucky as far as choice of very good filters: Formatt-Hitech Firecrest Ultra (disclaimer: am an Ambassador), NiSi, Breakthrough are all pretty good, even if I prefer the Firecrest because their coating is bonded in-between two thin panes of glass rather than applied to the exterior of the filter. A while ago, I did a little controlled test and compared a few brands, you might find this of interest:
https://www.vieribottazzini.com/2016/07/best-filters-landscape-photography-review.html
What I found amazing of that little test is how the Lee Stoppers, which when I "grow up" photographically where the end-all filters, don't just have a little cast, but are in truth painting everything extremely blue
Which, in turn will require to push the green / red channels to balance, and we know how the green is much stronger in Bayer than the red, thus potentially (and almost inevitably) creating noise in the red channel.
Hope this helps
Best regards,
Vieri