Please help. I don't understand the electrical box number puzzle. You gave the code but didn't explain..

Please help. I don't understand the electrical box number puzzle. You gave the code but didn't explain the logic, and I won't move forward with a game unless I can figure the logic out myself (with some help in certain cases, obviously). It appears to be just red boxes on the map, with directions only indicated on the left hand portion. How did you figure out the directions elsewhere to come up with the final code? I assumed there was multiplication involved (relating to the colors) and did that on my own before looking at your solution, but I came up with something different. Arrg, can you please give more guidance about the logic of this one?