Am happy to give away spare seeds if anyone wants them:
Laitris - purple but they take a few years to flower
Allium - Purple globemaster - again they take a few years to flower
Lupin - white and purple perennials - should flower late next year
Eryngium - tall silver thistle like with purple flowers
Echinacea - purple, these seed well and flower in one year
Blue Festuca grass - not tried to grow from seed but they should grow true.