Changing the theme of the forum

Looking / searching I get/find:

But alas that is for an older version of the forum.

I can't find the settings to adjust the theme.
(or am I missing something?)

Found it!
Sorry.

(If you are interested.)

Click on your icon (top right)
Pick the bottom icon from the drop down list. (Profile)
Then pick preferences

Then continue as per original post.