Q:

Does LaTeX consider text color?

In The Elements of Typographic Style (version 3.1, p. 25) by Robert Bringhurst I read:

the density of texture in a written or typeset page is called its
  color. This has nothing to do with red or green ink; it refers only to the darkness or blackness of the letterforms in mass. Once the
  demands of legibility and logical order are satisfied, evenness of
  color is the typographer's normal aim. And color depends on four
  things: the design of the type, the spacing between the letters, the
  spacing between the words, and the spacing between the lines. None is
  independent of the others.

As a user, I typically specify the type and its size as well as the line spacing, whereas LaTeX chooses the spacing between words and letters.
All four attributes determine the text color.
Does LaTeX try to achieve an appropriate text color by taking into consideration my choice of type?
If so, how does LaTeX do that?

A:

The question is starting from an incorrect assumption.

whereas LaTeX chooses the spacing between words and letters.

LaTeX has almost no control over the space between letters and normally does not control the space between words. Both of these are specified as part of the font metrics so they are part of the font design. So effectively you are choosing these things when choosing the font, and the overall effect is a choice of the font designer (or at least the person who set up the tex font metrics for that font)

