According to Hutching's, filter manufacturers dont take into account the altitude, colour temperature or the colour of the subject. Cant say I know anything much about all that but I use his method and his compensations and they work consistently.

For an example Hutchings recommends adding a two stop exposure increase when using a #25 medium Red Filter, that is after metering the important shadow areas through the filter. Metering the shadow areas though the filter is an important part of his method.

In my experience this method would provide me with detailed printable shadows.
Without the 2 stop compensation the zone III shadows would be lost in zone I.