Selective color?

[JohnRushing]

I decided to see what a photo I had taken would look like in B&W with the only color in it being red but it seems school has wiped out that part of my memory. I remember some of it but keep running into a dead end. I went into Layers and did the duplicat layers, then into new adjustments layers to Hue/Saturation and removed all the color. I then went to Group the previous and finally to Layers and selected background. When I try to bring the reds back into the photo I get all the colors. Anyone know where I went wrong? I know it's something simple but I've strained my brain for two days trying to remember how to do this. This is also the first chance I've had in two weeks to even play with any photos with school going on. Help!!!!!!

[rphoto]

Erase where the red should be in the b&w and the red will show up.