To obtain a proper color balance forget about using subjective techniques, such as looking thru filters. On every roll of film shot (or when using a different emulsion or lighting conditions) shoot a photo of a gray card. Make a print of the grey card; use must have a reflection densitometer to read the grey card. Measure the cyan, magenta and yellow- perfect color balance is obtained when you get 0.8/0.8/0.80 for the c/m/y. This is an infallible objective technique, which I have been using for many years. Incidentally, I use an X-Rite 404 reflection densitometer.