unreadable color: how to change lisp comment color (and find its font face)?

[Markus Dehmann]

I use color-theme, and I like color-theme-xp (sorry!). However, there
is one disturbing thing about it: It shows lisp comments (e.g. in
my .emacs) in the same color as the background! How can I change that?

I know I can do M-x color-theme-print and it prints the function for
the color theme, which I can modify. But I don't know what font-face
is used by lisp comments, so I can't change its appearance.

How can I find out what font-face is used by lisp comments so I can
change its color?

Thanks!
Markus