I have 2 dark complected boys and neither were premature. And both have hemangiomas. My oldest has a smallish on on his back that is all but gone now that he's 4 and my youngest has a more prominent on on his forehead which is well into involution and had faded a huge deal. Still a long ways to go with his, but the difference just in the last year is pretty neat!
Me - Aimee - Spot on liver
Elliot, 9/20/06 - H on back (nearly gone)
Felix, 7/28/08 - H on forehead (in involution)
Taking the 'wait and see' approach, for now.