After scanning the line drawing onto my PC, I used Corel Draw to make cut lines where the shaded and highlighted areas were going to be.

After that I filled the areas with color. I wanted to bigger guy in the back to have a yellowish green color to represent fear and jealousy. The child reading I wanted to be more innocent so i gave him the red and white propeller hat and added pink to his cheeks.
The next step was to create a background. I wanted to do sort of a paint dripping feel but unfortunately was limited to the artistic media tools since I don't have a drawing tablet. Luckily there was a tool close enough to what I wanted so I created this background and added a gradient underneath.
And that was it! I'm really happy with this one and I want to do more work digitally. Guess its time to save up for a tablet.Cheers.
