This use of local color is discussed elsewhere.

Perhaps the writer wishes to make character the dominant element.
Then he subordinates plot and setting to this purpose and makes
them contribute to it. In selecting the character he wishes to
reveal he has wide choice. "Human nature is the same, wherever you
find it," we are fond of saying. So he may choose a character that
is quite common, some one he knows; and, having made much of some
one trait and ignored or subordinated others, bring him before us
at some moment of decision or in some strange, perhaps hostile,
environment. Or the author may take some character quite out of
the ordinary: the village miser, the recluse, or a person with a
peculiar mental or moral twist. But, whatever his choice, it is
not enough that the character be actually drawn from real life.
Indeed, such fidelity to what literally exists may be a hinderance
to the writer. The original character may have done strange things
and suffered strange things that cannot be accounted for. But, in
the story, inconsistencies must be removed, and the conduct of the
characters must be logical. Life seems inconsistent to all of us
at times, but it is probably less so than it seems. People puzzle
us by their apparent inconsistencies, when to themselves their
actions seem perfectly logical. But, as Mr. Grabo points out, "In
life we expect inconsistencies; in a story we depend upon their
elimination." The law of cause and effect, which we found so
indispensable in the story of plot, we find of equal importance in
the story of character. There must be no sudden and unaccountable
changes in the behavior or sentiments of the people in the story.
On the contrary, there must be reason in all they say and do.

Another demand of the character story is that the characters be