Re: Problem with defining a background color by variable

[suzee]

> What is mycolor's value?  When is that value being set, relative to
> the time the above defface is processed by Emacs?

It's set right before the defface command and its value is #0000e6 
(checked with message outputs).  My code looks like this:

    (require 'color)
    (defvar mycolor (color-lighten-name "navy" 20))

    (message "My Color value: %s" mycolor)
    (message "My Color Type: %s" (type-of mycolor))
    (message "My Color is of string type: %s" (stringp mycolor))

    (defface org-block-background
      '((t (:background mycolor)))
      "Face used for the source block background.")

    (require 'org)


>> What can I do to make it work or to achieve my goal in a different way?
>
> My suggestion is to use set-face-background instead.  defface is
> effective only once, when the face is being defined.  Thereafter you
> can use set-face-background to change the background color.

Ah awesome!  The following does in fact work:

    (set-face-attribute 'org-block-background mycolor)

And it's nice that it allows to change it at any moment.  (I only found 
set-face-attribute by googling and couldn't make it work.)

Thanks a lot! :)

I'd be happy to understand the error message though to gain some 
knowledge about elisp.  Any idea about that?