Husband keeps posting color photos on our Daily Photo blog and the B&W version on his own Sketchbook, which, considering the ease with which it can be done digitally, feels like cheating to me. (Making the warp, winding/threading/sleying if we wanted to that!!) Nevertheless, it can be a valuable value study for me. Sometimes they become completely different photographs.
The latest I've been looking at is this annoying tiny bird that chases away birds three times its size from our fig tree: B&W vs color. I was annoyed the color version was so green, and the color of the bird is "inaccurate" (in my mind, though Ben say it's close), but was surprised how much softer the bird looks in the B&W.