Thanks!
The problem is more prosaic - the enlarger is so smart and computerised, that I can't figure out how to set color filtration for B&W exposures at all
How do you set it for color printing? Can't you specify Y and M filter values? The enlarger doesn't need to know that you are printing B&W.
I never used a big Durst, so a description of what settings are available might help.
Eric