Coloring is about relaxation and fun, not about speed. Beautiful results come from spending the time to shape a color, usually with the merest whisper of touch. Definitely not difficult or tricky, it takes some knowledge and practice that goes beyond the elementary filling of a shape with color. This is the first step in learning what colored pencil can and cannot do. And it must be said that remarkable things can be done with colored pencils.
Here are examples of filling a shape with a single color. Print practice page. Practice filling in a shape with just one pencil, any color. The first example below is quickly filled in without much attention paid to the edges and the corners. Note the strokes all go in the same direction except at the ends.
The next example is more completely filled, and the strokes go in many different directions for a smoother effect. The edges and corners are more carefully filled and the white of the paper still shows through.
The third example is more completely filled without any of the paper showing through. What shows through is a lighter layer of the same color. Colored pencils will not completely and evenly fill in a shape. To avoid white showing through, it works best to first fill with a light layer of color, then go darker. Going dark immediately creates ridges in the paper from the pressure of the pencil which are hard to color evenly.
Here is where you’ll learn that the paper will only take a certain amount of color. Colored pencils will always give a hand colored look. There are blenders pencils and pens available that will smooth out the color somewhat. Practice with other colors and you will find that some colors will be easier to smooth than others. Expensive pencils will perform differently than inexpensive ones. They both have their advantages.