what will a FL-Day filter do for black + white film?

what will a FL-Day filter do for black + white film?

Will it work like an orange filter?

I believe the FL-Day filter was somewhat magenta to absorb the 'excess' green of the fluorescent tubes to daylight balanced film and as such it may darken any wavelength in that part of the spectrum when used with B/W film... If I have time later, I will check my copy of Kodak's publication on filters for scientific use.

Ken

Since FLD and FLW filters aren’t intended for B&W film they likely offer no advantage. Otherwise they would be in common use for B&W film.

The only way to be sure is to test it with your film. Then you’ll know. The effect is likely to be modest.
Both the FLD and FLW are listed as holding back 1 stop.