I think Adobe photoshop is great for coloring any object either a black and white photo or scatch .Here is a easy and simple method to color a manga or anime or cartoon in photoshop .
First import image in photoshop
Then select magic wand tool in left tool bar
Then select any part of image you want to color e.g. face .(select all face parts by pressing shift and also save every selection so that you can load it any time )
After this select brush (airbrush with feathered edges)
choose a proper color for face
Set color blending mode multiply then color it
Now we select hairs by doing this (set wand tool tolerance 100 so that it it can select most pixels )
Now again select airbrush with diameter more than 160 and blending mode multiply and color hairs with your desired style .
Now see the image you will find some white pixels uncolored .To color these pixels select airbrush and set diameter 3 or 4 and zoom the image and color these white dots without making a selection.
Now color shirt with this method .
