Tell us about yourself!
If I were to sell you one, I would have to charge you for my material and time. It takes many hours to build, so the cost would be very high (Several hundred dollars) . But... here's a better idea... simply purchase a similar device as mentioned in Step 9 above. You may need to modify it to accommodate larger cells.
Sorry - I don't understand your question... You are asking about something 'orange color' in the code? Source code is text - no colors in it. Perhaps there is something that your editor puts in.
Nice job - I like the layout with the attention to high-wattage resistors and thick wire.