
B&W, curves stretched to increase contrast.

Colors with same curve stretch.

"Ken made me do it!"
OK, I confess -- I was testing a new copy of a lens, and since the maple leaf subject was unrelentingly GREEN, I decided to try rendering it in B&W to get some eye relief. Pic #1 is like the camera saw it (with a bit of sharpening), pic #2 is the same image converted to B&W in Photoshop plus some curves adjustment to punch it up, and pic #3 is the color image again with the same curves adjustment.
To my eye, it's pretty obvious that a curves adjustment that looks just fine in B&W is flat-out garish in color. And I think in this case, I like the B&W rendition best of the bunch.
FWIW...
--Rik
Technical: Canon 300D, Olympus 38mm f/2.8 bellows macro lens at f/2.8 and maximum extension, moderate crop. Stacked at 0.0005".