There are many ways to use Photoshop to color lineart. This tutorial demonstrates the method I use. It was created using Photoshop CS2 for PC. Newer versions may need slightly different steps. It also assumes that you are somewhat familiar with the software. :)
Coloring art in a program like Photoshop is not only fun (because you can get very creative using the tools and filters) but it can also save you time and materials, since you don’t have to worry about dry markers, broken pencils, or possibly starting over because of a mistake! You can also recolor the same image many times to see how different color combinations look.
Although following the tutorial exactly will help you replicate the same effect that I created, the best way to learn is to experiment and create your own results!
Before moving to this stage, I prepared my lineart using the steps outlined in my Digital Inking tutorial.
The Secret: Layers
The “secret” to coloring in Photoshop is to use layers so the colors remain separated. This makes it easy to avoid mistakes and will keep your lineart in pristine condition.
Notice the Outline layer is above all the color layers in the stack. Because of this, the colored areas will appear “seamless” and all the little white areas can be eliminated.
I typically name my color layers according to the color being used on it, although sometimes I will also use layers for specific parts of the image, such as “Hair Shine”, “Eye Highlight” or “Helm” in this example. Whatever way you name them, just remember to put each color on its own layer.
Why? Let’s say you pick a shade of green for the accents on your character’s clothing. Halfway through coloring the picture you decide that the green just isn’t working and you want to change it to purple. Now, if the green is with other colors on the same layer, changing it is a lot harder than it has to be. You could use Photoshop’s “Replace Color” tool or the Magic Wand but these can be tedious and inexact. If the green is on its own layer, you can lock the transparent pixels and then fill the layer with the new color. The new color will only appear on that layer where you colored before. This changes it everywhere at once without worrying about missing anything or accidentally messing up another color that you wanted to leave alone.
Start the Layer Stack
To begin coloring your picture, hold down ALT and click the “New Layer” button on the Layers Palette. Decide what color you’re going to start with and name the layer appropriately.
If the new layer is not directly below the Outline layer, click and drag it into position. If you still have your Sketch layer in your document (see the Digital Inking tutorial), turn the layer off by clicking the Eye (or, delete the layer, if you know you no longer need it).
Some people like to color one area at a time right to completion. They’ll pick, say, the pants, and do everything that needs to be done, including shading, highlights, special effects, texturing, etc. I don’t recommend this, because if you decide later you need to change something about what you’ve already colored, you already wasted a lot of effort.
If you build the entire picture as you go, you’re less likely to end up with extra steps. Some people call this a Color Test or Flats, which allows you to get an idea of how well your colors are going to work together before you start getting into the finer details.
You can go about this part two ways. The first way is to use the Brush tool to manually paint in the color in all the areas the color applies to. Nothing wrong with this, but if you have a large image it can take some time to cover everything as well as do the clean up work along the lines afterwards. The second method is to use the Magic Wand Tool to select all the areas of your Outline that should be that color and fill everything at once, which can save some time.
To use the Magic Wand, press W. Switch to the Outline layer. If you haven’t already, lock the Outline layer so you don’t accidentally draw on it. With the Magic Wand, start selecting all the areas that will be the color you have chosen first. You can select multiple areas at once by holding down SHIFT after you have made the first selection (or click the “Add to selection” button from the Options toolbar). If your outline has any holes in it, you’ll end up selecting more of the drawing than you want to. Deselect everything, unlock the Outline layer, and fix the holes before continuing.
Once you have everything selected, choose Select > Modify > Expand from the menu. Specify 1 pixel and click OK. This makes your current selection 1 pixel larger all the way around, which helps eliminate some clean up work later. This works especially well when most of your lines are at least 2 pixels thick.
Switch to the color layer. Be sure the color you have chosen is the Foreground color and press ALT+Delete to fill. Then press CTRL+D to drop the selection.
Repeat those steps for each color in your image until all the flats are done: Create a new layer, select the appropriate areas from the Outline layer, expand the selection, then fill the color on the color layer.
After all the colors are done, ensure nothing is selected by pressing CTRL+D.
Flats Clean Up
Now it’s time to clean up the image. The Magic Wand tool will not have filled in each area completely, as shown in the picture at right. There may also have been some areas too small to select which are still blank.
Press B to select the Brush tool. You’ll need a smaller brush; start with a Hard Round about size 5. You can use the square bracket keys ([ and ]) to enlarge and shrink the brush as needed.
Zoom in and work progressively through each color layer, filling in these “artifacts”. Treat this part just like how you would color if this was a coloring book: stay “inside” the lines but ensure the entire area is filled with no transparency left over. Press the spacebar to get the Hand tool, which will allow you to easily navigate around the image.
This is where having a tablet comes in handy. It’s not impossible to color effectively with a mouse, but a tablet makes things much easier because the shape of the pen is much more intuitive, allowing for more control and natural-looking strokes.
As you fix each layer, Lock it to preserve your work (the padlock icon on the Layers Palette). It’s near the top, just above the layer stack. To unlock the layer, click the padlock icon again.
Color and Shading
Now your Flats are done. Assess the overall image, and make any changes to the base colors now.
To begin shading, return to the first color layer in your stack. If it’s fully locked, unlock it and then duplicate it using CTRL+J.
Relock the original layer and switch to the new one. Rename the new layer as that color’s shadow and change its blend mode to Multiply.
The color on the shadow layer is now darker than the original color layer. Decide where your light source is coming from, press E for the eraser, and erase the parts that are supposed to be lit. This takes a bit of practice to get used to, as artists normally paint shadows on rather than “taking away” to reveal highlighted areas. If you’d rather paint the shadows by hand you can; simply create a new, empty layer set to Multiply, and paint with the original flat color.
If you want more levels of shadow, create more layers set to Multiply and erase the parts that aren’t needed (or paint on manually, still using the original flat color). For highlights or other effects, create new layers set to Normal (or experiment with other blending modes such as Lighten) and have fun!
Keep the layers locked until you are ready to work on them. While working, use the transparency lock so you only color where you’ve already filled in.
Add a background by using the Background layer already in your document or by creating a separate layer (I usually choose a separate layer).
There are many other options (such as folder groups) to help you keep your layers organized and your picture looking good. Be sure you explore and try things out!
Tip: Your lineart is on its own layer so you can lock its transparency and color it to enhance your drawing. You’ll have to be a little more careful doing this since you’ll be using more than one color on the Outline, but give it a try and see what happens. :)
This coloring technique, like anything, takes some practice, but once you get the hang of it, you’ll end up with a fabulous looking picture!