Grey on Grey is hard to read

[Bruce Korb]

Hi,

I need to use color because weaving in doc comments
renders the code unreadable without it.  However, in
C the preprocessing directives are day-glow pink and
strings are grey on a grey background.  I cannot read
it and I cannot fix it.  Apropos "color" yields nothing
at all (of any use) and apropos "font-face" yields
stuff too confusing to deal with.  Similarly, reading
"font-face.el" got me nowhere.  All I want to do is:

1.  Learn what colors are available
2.  set the various syntax colors to values that
    can be read
3.  Change the background color from grey to black or white.

Thanks!

P.S., I've been to the "FAQ", but the word "color" doesn't
appear on the page, either.

Oh, my platform is Sun Solaris on Sparc with emacs 20.7