I assume you would like to maintain the white appearance of your porch (since you could have chosen a different color). Instead of trying to hide its appearance why not try to break up the brightness by placing a few objects along its edges. Large planters, small table, etc. You could even try to hang some planters or objects on the house. This will break up the total white look and even cast some shadows to help dull the brightness.
Another thought is to place a trelis along the length of the porch or over the entranceway. Vines could be trained to grow along it to help block the hot summer sun and allow you some shade to once again offset the brightness.