Hi Michele... yeah but only by hand... youd have to use alot of layers and patience but it can be done.

heres one of me as a mere child (lol) that was b&W and i colored in Photoshop, I couldnt find the original but thes was one version while in the middle of working on it. you can see the BG wasnt colored yet..

Here is the finished copy

and here is one of "harry perrigo" the original owner of the company I work for, this is the first one I ever did so its a bit rough..

So, t can be done. I used Photoshop CS3 for these.. Oh I do have a pen tablet too, it makes things much easier.