Converting to black and white using Black & White adjustment layers

So far, I've been applying the black- and-white conversion tool by opening an…image and going up here to Image > Adjustments > Black & White, and when I do…that--like I am doing right now, and this is just the same thing we've seen before--…I'm going to make a couple of adjustments to the sliders, hit OK, and when I do,…the black-and-white adjustment is applied to my color image in a destructive…manner, meaning my original pixels are irrevocably altered.…The color image is gone; this is now a black-and-white image.…Yes, I can undo to get back to my color image, or redo to get back to black and white.…

But as soon as I make one more error, I can't do that anymore.…And if I save the image then for sure it is henceforth a black-and-white image.…The problem with that is if I want to keep the color version I have to keep…separate files and so on and so forth, and more importantly, if I decide well,…I'd like to darken that blue sky a little more, I can't get back to those tools in any way.…So, a much better way to apply the black- and-white conversion in Photoshop is to…