Setting text properties in Emacs when using font-lock-defaults

Question

I am trying to set some background text properties in my Emacs buffer. For instance,

(set-text-properties pos1 pos2 '(face '(:background "cyan")))

But I cannot get it to work. I think I have a clue why it does not work: I am also using a major mode that uses (setq font-lock-defaults '((some-font-lock-keywords))) If I comment out that assignment to font-lock-defaults it works fine.

Answer 1

Here's a bit of code that you can paste into *scratch*:

(let ((inhibit-modification-hooks t))
  (make-face 'temp-face)
  (set-face-background 'temp-face "cyan")
  (put-text-property 1 50 'face 'temp-face))