It is a a snapshot of a .gif file obatined from the above reference. It can be created using paintbrush. Different colors are used to represent the various aspects of metabolism, to simplify the map. For example, carbohydrate metabolism can be traced by shades of the blue color as shown in the map, dark blue represent carbohydrate metabolism and sky blue represent complex carbohydrate metabolism. Different shades of green represent Lipid metabolism.
Shades of orange is used to represent protein metabolism.
The pixels represent metabolities. The key to the map is embeded in the map. Note that there is no key for each pixel. Therefore, this map is geared for an audience with intense biological knowledge. However, the map even though intense with information allows to viewer to see that metabolism is a very complex process.