I am obviously now known as the local "pusher" of greyhound hardcore.
Black dogs of all breeds are usually harder to home - all sorts of theories, ranging from the fact they can look more threatening and less appealing to the roots of folklore and tales about giant black dogs. In studies, has also been confirmed that in a shelter environment, black woofs are last to be chosen, along with a bias against larger, male dogs. So if you are a large, black male dog, you will have a harder time getting a home. 
Don't understand it personally, as two of ours are black and I LOVE their colour, as nothing gleams like a black coat in good condition - it's like silk. However, we'd got ourselves organised and had ensured a bias towards black clothes (my inner Goth emerging) as everything was covered in hair (don't believe anyone who tells you greys don't shed). Then of course we ended up adopting our third who is a beautiful blonde - so now everything we wear will show up either the black hair or the blonde. 