ediff - change colors and how to merge code

Question

first question: is how to adjust colors of ediff-revision output, tried various versions - no luck:

;; Customizing colors used in diff mode
(load-library "ediff")
(setq ediff-window-setup-function 'ediff-setup-windows-plain)
(setq ediff-split-window-function 'split-window-horizontally)

(defun update-diff-colors ()
  "update the colors for diff faces"
  (set-face-attribute 'diff-added nil
                      :foreground "white" :background "blue")
  (set-face-attribute 'diff-removed nil
                      :foreground "white" :background "red3")
  (set-face-attribute 'diff-changed nil
                      :foreground "white" :background "purple"))

(eval-after-load "diff-mode"
  '(update-diff-colors))

;; Usage: emacs -diff file1 file2
(defun command-line-diff (switch)
      (let ((file1 (pop command-line-args-left))
            (file2 (pop command-line-args-left)))
        (ediff file1 file2)))

(add-to-list 'command-switch-alist '("diff" . command-line-diff))

;; turn off whitespace checking:
(setq ediff-diff-options "-w")

(provide 'ediff-settings)

second: How to merge the changes from left to right but only a selected portion / changed block?

Answer 1

first question: You can custom a face like this:

(custom-set-faces
 '(ediff-current-diff-A ((t (:foreground "White" :background "brown")))))

the ediff faces are:

ediff-current-diff-A 
ediff-current-diff-Ancestor
ediff-current-diff-B 
ediff-current-diff-C 
ediff-even-diff-A 
ediff-even-diff-Ancestor 
ediff-even-diff-B 
ediff-even-diff-C 
ediff-fine-diff-A 
ediff-fine-diff-Ancestor
ediff-fine-diff-B 
ediff-fine-diff-C 
ediff-odd-diff-A 
ediff-odd-diff-Ancestor
ediff-odd-diff-B
ediff-odd-diff-C

second question:

Where you are on the changed region you can use a or b to copy the region from left to right or from right to left.

Hope that helps

Answer 2

Move to the coloured text you're interested in, and type C-uC-x= to view details of the character at point, including any faces.

Select the face you're interested in, then select "customize this face", make the desired changes, and save.