Do dark skinned people have thinner blood than light skinned people?

Answer 1

Skin color generally has nothing to do with with how thick blood is. It is primarily a function of how much pigment is in the skin.

There are some medical conditions that will darken a person's appearance. One of them has to do with having an excess volume of blood. In the case of one of these medical conditions where blood is in excess or thicker, it may give the person a somewhat darker complexion, but we don't usually refer to such a patient as being "dark skinned" - it's more like they have a darker blush.