How to customize TinyMCE dialog CSS?

Question

I'm trying to get custom CSS control over TinyMCE dialogs/modals but not getting anywhere and not finding clear instructions for this in the Docs. I'm using TinyMCE 6 (the latest version).

I'm able to successfully control the main editor CSS with either of the following:

tinymce.init({
  content_css: '/somefile.css',
  content_style: 'some CSS rules',

But this is not affecting the dialogs. There is a note in the Docs to use the following syntax for dialogs:

tinymce.init({
  popup_css: '/somefile.css',

But this is also not having any effect. It's as if any CSS rules relating to dialogs using any of these methods are completely ignored.

Has anyone done this and could point me in the right direction? Thank you.

Answer 1

In TinyMCE 6 you would control the look of the dialogs via the skin you use with TinyMCE.

The documentation for this in TinyMCE 6 is here: https://www.tiny.cloud/docs/tinymce/6/creating-a-skin/

Note: The popup_css option you reference was from TinyMCE 3.x and has no impact on any current version of TinyMCE.