I have been doing most of my post processing in Lightroom (v4) for quite a while and I very seldom use Photoshop. Bust there are some limitations in LR4 and PS is perfect for performing many tasks not available in LR. Above is a photo from a converted (from the Wolverine) black and white negative shot specifically for hand coloring. I liked hand colored photos and even got pretty good at it but it was a time consuming and sometimes tedious endeavor and the results were variable. PS makes hand coloring a pleasure compared to the traditional method and it is non-destructive.
To get this look, I toned the photo, spotted out the dust spots and cropped in LR. These changes are all reversible as an advantage. In Photoshop, a blank layer is added above the background layer (this photo) and the blend mode is set to Color. I start with the deep green color selected from the pallet and brush over the area with the brush set at 100% opacity. This eliminates any streaking. Then I set the layer opacity to a lower number, in this case 35%. You can use the eraser tool to remove any over-brush. Then another blank layer is added above this, set to Color Blend Mode, and this time I used a deep yellow color with a slightly softer and smaller brush. The layer opacity was set to 35%. Then I did the same thing with a deep purple color. The extra layers don’t add much to the file size so you can save the file with all the layers and fine tune it later on if necessary. Of course, if your shot is originally in color it’s very easy to get this effect.
…and then you get to eat the asparagus!