"Black Dog Fridays"

Statistically, black dogs are the last to be adopted and the first to be euthanized at shelters.  There are three reasons for this:

1. At about age 12-14, we as humans form the subconscious opinion that good is white and bad is black.  As youngsters, we look at dogs without really seeing color but as we become pre-teens, we start forming judgments on what a dog may be like in personality based upon his coloring.  Movies don't help this conception either as the 'devil dog coming out of the dark mists' is usually a big, black, evil looking dog.
2. Many of the powerful, 'bully' dogs are black in color naturally - Rotties, Dobies, German Shepherds, etc.
3. People square off their shoulders and look directly at dog - in dog language this is a challenge and/or potential dominance.  Watch two dogs approach each other - chests out, ears up, shoulders flexed.  To add to this, because we humans are visual creatures, we tend to stare into anything we are trying to bring into greater focus.  And a black dog with black eyes is hard to make visual contact with... with all of this going on, the black dog with black eyes is going to either accept the challenge of the human stranger or retreat back, making them appear less adoptable in a kennel or shelter situation.

To make it easier for black dogs to be adopted more readily, TLC runs a program called "Black Dog Fridays" where any black dog is discounted 20% off of the adoption donation (adults or puppies alike).  We started it on "Black Friday" after Thanksgiving in 2012 and it has proven to be effective in finding black dogs furever homes.

For more on this, simply Google "Black Dog Syndrome" or read Wikipedia's page.