Changing filter settings means you need to change the exposure also. When I (totally not an expert at RA4) do this, I:
* get the exposure right within about half a stop
* adjust the filter pack to get colour exact
* adjust the exposure again to get the highlight/shadow detail I want
Because the filters work by attenuation, changing them will change the density as well as the colour, so you can't avoid that final step of tweaking exposure.