Hydrangeas prefer afternoon shade, especially during the summer months. Of those, paniculatas can handle the most amount of sun. But in the northern half of the country, you can plant paniculatas/oakleafs/arborescens in almost full sun. You can even see paniculatas grown as small trees in the Northeast.

Should you notice that leaves in direct contact with the sun begin to turn ALL yellowish/whiteish (including the leaf veins), transplant the plant to a shadier location. You can also check where others have already planted their hydrangeas in your city.