Jessica, I have a possible explanation for your dream.
1. You like turtles.
2. You wanted to see a young, baby turtle.
3 You are concerned about painting your front door, and want a fresh, new color.
4. You are considering the color red.
I think that there is an association between the red front door (which perhaps represents a fresh, new life) and the red turtle. Seing a baby red turtle is kind of a convergence of the two things.
Oversimplified, perhaps, but I don't take too much stock in dreams. Our brains are so incredibly amazing, complicated, & constantly stimulated. I think that dreams are created by impulses caused by confounding "moments" that perhaps occurred during the day, or "De-Ja-Vu" moments. I sometimes think that dreams are like the "electrical recapitulation" of events, but are separated from real time.