Wiring is something that professional, licensed, insured electricians do everyday.
It takes no time at all for them to install the proper wiring and receptacles in your home.
Having your electrical wiring done correctly is important for your safety, as well as the proper operation of your appliances.
The 120/240 volt wiring is normally used for clothes dryers and kitchen ranges.
The 240 volt line is for the motor of the appliance and the 120 volt is for the timers and lights or any other controls you have on the appliance.
There is a difference between wiring, color codes and receptacles.
Since most people do not understand these differences, it is always better to have a professional do the job.