Hydrangea macrophyllas (like Nikko Blue or Endless Summer) and Hydrangea arborescens (like Annabelle) won't work with afternoon sun, but Hydrangea paniculata will be fine even in all day sun, so you should be in good shape if you use one of them. They range in size from the small Bobo at 3'-4' tall to ones that grow to something like 8'x8'. Limelight, Quickfire, Vanilla Strawberry, Pinky Winky are among the many H. paniculatas available. All go through lime to white to pink shades, but have different levels of color intensity and spend different amounts of time in each of the colors. Blossom shape and density varies between cultivars as well. I like them because they have no issues with disease or insects and are really hardy for all of New England (to zone 3). My Quickfire blooms from the beginning of July until frost, and the others start anywhere from early July to early August, and then will bloom until frost so they are really long blooming.