I came up with a much better compromise and painted both sides of the door. Now the color that I love is on the interior. I see the exterior door when I pull into the garage, but I see the interior side all the time. Win-win!
Here is the interior shot of my entry when I moved in 4 years ago. Stark, cold white. I had painted the wall to the right to warm the space and changed the color the day before painting the front door. The hallway seemed to go on forever like a bowling alley.
Painting 3 coats of Valspar Swim. I painted 2 coats with a brush and rolled the final coat. The gray paint was much thinner and just bubbled with the roller, so I only used a brush. If I lived closer to Lowe's, I probably would have returned the paint and asked them to remix. I've never had a problem with Valspar paint, but I was not pleased with the consistency of the gray. A painter friend confirmed that the paint shouldn't have been so thin.
We also replaced the weather stripping on the bottom of the door while it was off the hinges. Much better! There was a crazy gap/draft that I should have fixed two years ago instead of using that dumb weather guard thing that just made it difficult to open/close the door over the run. Here are the two colors I used on the door: