Emacs - random color theme every hour?

Question

I know that to (funcall (car (nth (random (length color-themes)) color-themes))) gives me a random color theme on every Emacs startup; but I hardly restart Emacs. How do I cycle between random color themes, say, every hour?

This sounds horrendous :) Is the idea to randomly select colour schemes until you stumble upon one that you want to keep? — phils, Aug 15 '10 at 23:22

Sridhar Ratnakumar · Accepted Answer · 2010-09-03T00:20:11.197

9

(defun random-color-theme ()
  (interactive)
  (random t)
  (funcall (car (nth (random (length color-themes)) color-themes))))

(random-color-theme)

(run-with-timer 1 (* 60 60) 'random-color-theme)

Credit goes to ggole @ #emacs (freenode); and aecrvol (below) for the (random t) tip.

edited Sep 03 '10 at 00:20

answered Aug 13 '10 at 23:50

Sridhar Ratnakumar

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I am getting an error `void variable color-themes`. What should I do as prerequisite? – jdhao Oct 01 '21 at 07:30

score 3 · Answer 2 · answered Aug 30 '10 at 17:47

A little improvment: adding to the function (random t), otherwise generated sequence will be the same in each Emacs run ( from http://www.gnu.org/software/emacs/elisp/html_node/Random-Numbers.html).

(defun random-color-theme ()
  (interactive)
  (random t)  ; randomazing
  (funcall (car (nth (random (length color-themes)) color-themes))))

score 1 · Answer 3 · answered Dec 05 '18 at 20:41

Here is my update:

(setq color-themes (custom-available-themes))

(defun random-color-theme ()
  (interactive)
  (random t)
  (load-theme
   (nth (random (length color-themes)) color-themes)
   t))


(random-color-theme)

(run-with-timer 1 (* 60 60) 'random-color-theme)

Emacs - random color theme every hour?

3 Answers3