Yes it does sound right. The wiring for the door sensors and the wall control is color coded and the color code must be followed for everything to work properly. The colors depend on the manufacturer. If you have decided on the opener you are going to install you should contact the dealer and see if you can order the correct wire.

"The colors depend on the manufacturer."

You can use any color code you want as long as you are consistent. The electrons do not care about insulation color.

There is no reason to have boxes for the control wiring.
It is power limited and requires very little in the way of protection for safety.

You will need a 120 V receptacle on a circuit with enough capacity in the ceiling near the unit's location.

Unless the garage walls are to be finished with drywall, outside of the 120 V outlet there is no real reason to do anything ahead of time.