Choosing a color is a fun process in and of itself and Photoshop gives you such flexibility that color choice can be a beginning, intermediate or advanced task.
For the moment, let's focus on the basics of color. Essentially, choosing color involves two decisions: what color should your canvas be (background color in technical jargon) and what color paint should you use to draw with (foreground color)
Choosing foreground and background color is handled in the Toolbox. Near the bottom of the toolbox you will see the color picker squares The square on top is the foreground color and the square in back is the background color. (note that you can easily make the foreground color the background color and vice versa using the little switcher arrows
To change the color, you simply click on whichever square you want to change. When you do so, the "Color Picker Dialog" will appear.
Choosing a color is easy, you can choose a color by moving your pointer over the desired color in the color chooser square and clicking. Notice in the figure above that we chose light blue. You can see the exact hue highlighted inside the tiny circle in the color chooser square If you want to change the range of color, simply click on the color range slider to the right of the color chooser square. Notice that the your original color and your newly chosen color will be represented in the "Color preview box" to the right of the color range slider. in the case of the figure above, the old color was light purple.
Of course, the advanced user can define colors absolutely by their RGB, HSB or CMYK values. A complete discussion of the various modes of defining colors on the computer is beyond the scope of this tutorial, but truly, you don't much need to worry about it so long as you can use the color chooser square and the color range slider.
We are almost ready to start making a mess. But first let us take a look at the set of brushes we have at our disposal.