Re: Selective color w/black and white
Welcome to Retouch Pro. There are a number of ways to get there but here are a couple of conventional methods using Photoshop.
1. Duplicate the background layer. Convert the new layer to B&W using any of 10 methods. A simple Ctrl+Shift+U in PS will desaturate the layer.
Now add a layer mask. With the mask active (by default), choose your paint brush with the color black, and paint over the areas you want to restore color. If you accidentally expose the wrong area, just change the brush color to white and paint over those places to correct.
2. Same process as above but instead of adding a layer mask, select the History Brush and on the B&W layer, just paint over the areas where you wish to restore the color.