Once the flat color was done I decided to paint the black lines a different color. I used the eyedropper tool to select one of the flat colors from one of my characters.
Then in the color palette I selected a slightly darker color. This was the color I would give to the line surrounding the original flat color.
I then clicked on my Black Outlines layer and clicked the Lock Transparent Pixels button. This button enabled me to only color on the black lines.
With my Black Outlines layer selected, I chose a hard paintbrush and began to color over the black lines. I kept choosing different colors as needed and painted until every black line was colored.
I also masked out the black lines that were dividing my pages. To do this, I selected my Black Outlines layer and then clicked on the Mask button.
Then I selected the paintbrush, selected the mask layer and made sure my color was selected to black. I then began painting over the black dividing lines. This turned my lines invisible. I could have just used the eraser tool, but if I accidentally went over a line I didn’t want erased, I could then change the color to white and unmask any area I had accidentally masked out.
And here is the final image:
Next Step: Coloring in Photoshop: Part 4 - Shadows and Highlights