I was googling "porch ceiling blue" when I learned that its not a exact color, but the shade of blue. In the South, its referred to as "Haint Blue", as it was the blue that repelled restless spirits, aka Haints, and, coincidently, annoying mosquitos.
We decided on Sherwin-Williams' Atmospheric for the ceiling, and it looks just like I think a porch ceiling should look. Or will look. After Jeff finishes the painting.