a (of complexion, hair colour, etc.) not fair or blond; swarthy; brunette.

What does dark mean in tall dark and handsome?

Some say it is describing the color of hair. Others say it is a description of complexion or skin color. Still others insist that the term dark has nothing to do with looks at all, but is describing a person who has a mysterious air about them.

What does a tall dark stranger mean?

In Scotland, a tall, dark, stranger is a symbol of good luck in the tradition of first-footing. The idea of the 'tall, dark stranger' mentioned by a psychic is probably this one.