How do I get foreground and background colors of a face?

Question

I would like to print face color attribute, below code just print the name. how to print the foreground color and background color?

(print 'font-lock-function-name-face)

Answer 1

You can see the list of face attributes at face-attribute-name-alist

(defun dump-face-attributes (face &rest props)
  (cl-loop for prop in (or props
               (sort (mapcar #'car face-attribute-name-alist)
                 (lambda (s1 s2)
                   (string< (symbol-name s1) (symbol-name s2)))))
       for val = (face-attribute face prop nil t)
       unless (eq val 'unspecified)
       append (list prop val)))

(defun get-face-attribute (face prop)
  (plist-get (dump-face-attributes face prop) prop))

and you use it like this

(get-face-attribute 'font-lock-function-name-face :foreground)

(get-face-attribute 'font-lock-function-name-face :background)

(dump-face-attributes 'org-code)

Here is a sample session in M-x ielm using above functions

*** Welcome to IELM ***  Type (describe-mode) or press C-h m for help.
ELISP> (get-face-attribute 'font-lock-function-name-face :foreground)
"#4949d7"
ELISP> (get-face-attribute 'font-lock-function-name-face :background)
nil
ELISP> (dump-face-attributes 'org-code)
(:foreground "grey50" :inherit shadow)

Answer 2

You can use face-background/foreground for that. For example

(face-foreground font-lock-function-name-face)

(remember to also read face-foreground its docstring)