This is a popular genus of herbaceous plants, commonly known as yarrow, with soft, deeply dissected, spreading, silvery green leaves, which are showy in themselves. But the plants looks even better when the flat-topped clusters of many small flowers open. Wild species tend to be yellow or white, but there are many selected forms with a range of bright colours. They are excellent for attracting bees and butterflies.
Achillea 'Terracotta' has flowers that open light orange and gradually fade to creamy-yellow. At no stage would I describe them as terracotta!