It sounds as though you're describing purple fountain grass (Pennisetum setaceum 'Rubrum'). This colorful grass makes a striking addition to container gardens with its purple-maroon foliage and arching pink-tinged flower heads. It can also be grown in warm, sunny gardens as an accent plant or combined with flowering annuals and perennials. It is reliably hardy only in Zones 9 and 10. In colder zones, treat it as an annual.