One online coloring book, ColorbyNumbers.com, works by providing an outline of a picture divided into sections and labeled with numbers; users click numbered color tubes on the screen and the matching number on the drawing to color the picture. The site mimics the popular painting kit created in 1950 by artist Dan Robbins and paint company owner Max S. Klein.
Color by Numbers teaches preschool children math through play. If the user chooses the wrong color for a portion of the picture, the default settings stop the action and gives hints for the right hue by pointing to the tube in the menu. Each of the pictures has three levels of play: easy, difficult and numberless. The difficult mode divides the picture in to smaller detail for older children who have mastered the basics and the numberless version gives the artist freedom to create their own patterns.
Clicking on one of the nine tubes of paint produces a new multicolored tube in the horizontal menu header. Clicking on the icon produces a color chart; assign a new color for each of the tube by clicking on any point in the detailed color spectrum or choosing one of the 60 color swabs.