Race and what is perceived as an 'ordinary family'

 Whenever the media mentions an ordinary family or shows a film or tv series about an ordinary family, they are almost always white.
For example in the fantasy genre, the two programs I looked at both had all white american families classed as 'ordinary'.
What if the families were Black or of a different race to causasian?
What effect would it have on the viewers?
I did some little tests on this by changing the race of the families in No Ordinary Family and The Incredibles.
I got mixed reactions.
Better reactions from the incredibles poster because its of better quality.
Some people were shocked, some smiled and some people questioned as to why they were black