Trying something new

So I was playing around with my cheapo photo editing software and realized that I had no idea what my black and white "conversion" actually did. I always just used it with the red filter on, not realizing that I could filter with other colors and that would completely change the type of b&w photo I ended up with. Who knew? This first photo I filtered with green - 100%. I think it looks a little like a newspaper photo.

This one I filtered with yellow, or maybe it was orange? at 100%. Now I'm wondering what the pros recommend for b&w. Guess I'm off to research that now.