emacs - long line hightlight color too dark

Question

I use below code to highlight characters longer than 78.

(setq whitespace-style '(face empty tabs lines-tail trailing))
(setq whitespace-line-column 78)
(global-whitespace-mode 1)

It works fine but the background color too dark!

How can I change the highlight characters background color?

Answer 1

just like below:

(setq whitespace-style '(face empty tabs lines-tail trailing))
(setq whitespace-line-column 78)
(global-whitespace-mode 1)

(custom-set-faces
  '(whitespace-line ((t (:background "#eff0f1"))))

Answer 2

Just customize the whitespace-line face.