On the Subject of Corners

The solution is just around the corner.

• Observe the colors of the four corners of the module. They can be red, green, blue, or yellow.
• Find the locations in the following diagram corresponding to the relevant colored corners.
• Start in the location that contains the last digit of the serial number. Touch that corner on the module to begin.
• Find the shortest path through the diagram that visits all remaining corners and touch them in the order in which they occur in that path.