You did a good job on the repair so that's a start. Is the paint on the car relatively new or has it been on for awhile? You can match if you have the paint or the code for the paint to get some mixed. You must be really careful when shooting metallics air pressure and technique make a big difference in how the finish turns out.
As far as painting in colder temps.........first rule is the metal must be warm. The body temp should roughly be the same as the air temps you are sparying in. If the body is cold the paint will sag down the side.