Some of my earlier-blooming perennials have been brightening up my flower beds will all sorts of colorful blossoms. One of them is Centaurea montana or Perennial Bachelor Button.
This photo doesn't really do it justice but the blue is as intense as any gardener could hope for. They are super hardy and very easy to grow. Mine are growing in filtered shade but they like full sun, too. They grow to about 18" tall and the foliage is quite attractive.