Royal Purple has dark red/purple foliage and Grace is green leaved with purple/pink flower plumes. Grace also looks as if it is goingto have red foliage because new young growth is red turning green then red again in the autumn.

thanks scotsgran for the imformation,i think i have a very fine specimen of royal purple but the leaves on mine are a lot bigger than the one in my neighbours garden.perhaps someone has an explanation

Post a photograph of your shrub in case its something entirely different, desiray! Otherwise, cause of better growth could just be better growing conditions for it.