This is just a little FYI, possibly usefull, maybe not. Maybe someone can ferret out an idea of how Efke renders certain colors. I was looking for a scan of Efke 25 4x5 for an earlier topic and came upon this.

elearning.winona.edu/staff%5Fo/jjs/colors/

Here is a case where B&W wasn't the right choice. LF color would have been. IMHO