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.

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).

The color palette shows the conventional 28 colors. You may change or customize this palette by double clicking on any color. This will open a window for defining your own colors. Select the Define Custom Color button, click on an area of the rainbow box, click the Add to Custom Colors button.

This means there are 16,777,216 colors. Explanation: Some paint boxes have 6, 12, 30, or 48 pans. Some paint boxes also come with an unlimited number of shades that can be created by mixing colors.