The main purpose of the Colour Box is to develop a child's visual sense of colour. Primary colours (Red, Yellow and Blue) are introduced in Colour Box 1, which is first presented to a child at 2.5 to 3 years of age. Colour Boxes 2 and 3 add more tablets to the mix, expanding a child's colour knowledge.

Brown kraft and white are the most common shipping box colors because they are the two most naturally occurring colors of corrugated board. Choosing any other color for a shipping box requires printing the color onto the corrugated board. Typically, this process involves printing the color onto mottled white cardboard.

The Color box at the right of the window displays the currently selected foreground and background colors. The top color is the foreground (for drawing with left-click) and the bottom color is the background (for drawing with right-click with most tools).

Color is defined as the aspect of things that is caused by differing qualities of light being reflected or emitted by them. To see color, you have to have light. When light shines on an object some colors bounce off the object and others are absorbed by it.