Here it is
- Open your Black and White image in Photoshop
- Select the area you want to color by select wizard tool of that picture. Make sure this selection is for single color only. If you want different colors, you need to redo the process.
- Copy the selection on a new layer, this will make editing much easier.
- On the new layer , select Blending Options --> color overlay with appropriate color and opacity.
- Your Image is now ready
And you know how to change Eye and Hair Color :)