It is tricky to find just the right exterior red. Depending on the time of day and whether or not the sky is overcast can "change" the color.
Here is what I would do. I would get several paint chips that look like candidates. Tape them to the front door. Look at them at different times of day. Make notes right on the chip - time of day, pretty or not.
When you have narrowed down your choices to two, buy sample jars. Paint a 12x12 square on the upper half and lower half of the door of each color. Do the same test, looking at the colors several times during the day.
NOW you are ready to paint, or start new trials.
Sorry I can't just say, "Use such-and-so color."