Richard, I use both red and green filters in my portrait work, and all I can say is be careful!!!!(posted 8830 days ago)My experience is that when they work they really work & when they don't, they don't. By that I mean, I have not found a real predictable consistency when using them. Some faces and skin tones do well with one or the other, and until I get the print in front of me, I don't know. So, I tend to use it on people I photograph over a period of time.
You get some idea by putting the filter on the lens and looking through the camera, but it is no true indication.
So, if you are going to do important photos that you can't take over again, I would either stay away from filters all together, or use them on only selected shots.
Also, different films will react a little differently.
This discussion usually gets all kinds of divergent responses. You pays your money & takes your chances.
Good luck!
chris