Centaurea montana, the perennial bachelor's button is actually a cornflower blue colour that appears more of a lavender in my photos.
Open and sun lit, the soft and spiky petals show why this variety is attractive to bees. Bees seek out blue and yellow flowers.
Looking inside shows a tinge of pink at the heart of the flower.
Cutting back the stems after blooming encourages another flush of flowers. A drought tolerant plant that blooms from May-June in my zone 5 garden.