DOOM themes: color face for line that divides buffers

Question

I installed Doom themes on my Emacs. I would like to know how to manually change the color face of the vertical line that divides different buffers. By default it has a dark color not very undistinguishable from the background.

Answer 1

How to add window-divider settings to a theme

This is how one customizes a theme ... For this example I am using emacs -q and will describe the steps for customizing adwaita theme.

1. emacs -q
2. M-x customie-theme RET adwaita RET. Click on customize link.

3. The customization buffer shows all themed variables. adwaita doesn't provide any customization for window-divider faces or variables.

4. Go to the end of the customization buffer with ESC >, and use Insert Variable and Insert Additional Face to add faces and variabes need. You can also customize their values.

5. Go to the beginning of the customization buffer with ESC <, and press Save Theme. This is what you will see

6. On save you will also see a message saying where Emacs is putting the new customization file. In my case Emacs writes the theme settings to /home/whitetrillium/.emacs.d/adwaita-theme.el.

7. In the same session or different session, do a M-x load-theme RET adwaita RET. This is what you will see. Note the window-divider settings have taken effect.

8. FWIW, this is what the customization file for a theme looks like.

(deftheme adwaita
  "Face colors similar to the default theme of Gnome 3 (Adwaita).
The colors are chosen to match Adwaita window decorations and the
default look of the Gnome 3 desktop.")

(custom-theme-set-variables
 'adwaita
 '(window-divider-default-bottom-width 3)
 '(window-divider-default-right-width 3)
 '(window-divider-default-places t)
 '(window-divider-mode t))

(custom-theme-set-faces
 'adwaita
 ;; Existing faces Snipped
 '(window-divider ((t (:foreground "red"))))
 '(default ((((class color) (min-colors 89)) (:background "#EDEDED" :foreground "#2E3436")))))

(provide-theme 'adwaita)

---

adwaita doesn't provide custom window-dividers. But I see an entry for modus-operandi. So, when you are using custom themes YMMV.

---

As an aside, I think,

1. Emacs should display the currently active theme(s) in modeline. I frequently see people looking at screenshots, and asking "What theme?" is that ....
2. M-x customize-create-theme should interactively query for theme. Right now, the interactive invocation takes no arguments.

If someone is reading this, and if it makes sense, and its worth your while, please take the above requests to emacs-bugs or emacs-devel.

Answer 2

To get this

do this

(custom-set-variables
 '(window-divider-default-bottom-width 2)
 '(window-divider-default-places t)
 '(window-divider-default-right-width 2)
 '(window-divider-mode t))

(custom-set-faces
 '(window-divider ((t (:foreground "red")))))

---

M-x customize-apropos-faces RET window divider

Also look at

(info "(emacs) Window Dividers")

which can be reached through C-h r i window divider