Bruce Barnbaum told me a green filter would help when I was taking some photos from inside a building with the wintertime brilliant green grass of California glaring in the doorway.

Also let it be noted that early glamour shots used green filters or gree makeup to enhance portraits on black and white film.

You may not use it often, but there are times you will find it useful.

Now one that is hard to find but would also sometimes be good is a violet one.