I had created a new database a month or so ago before upgrading to 8.5.1 (from 7). I started going through the TLCC course and found out about themes. There are some style sheets, in the past, I would put on each form under HTML Head Content. Upon my excitement of themes, I quickly set one up and it works on all of my design elements (new forms just open), but it’s all lost when they are saved into documents…
In all my looking and playing, I have realized that much of the new “stuff” we can do in 8.5.1 is only valid if you start out totally as an XPage-type database and can’t use a non-XPage form even though it has a spot on the form to define themes…
???
I appreciate any help you can provide…
Debbie
Subject: Wait, hold up-
I haven’t seen that (theme properties on Forms). Let me check that out. Are you sure you’ve got focus of the form, and not the application/database?
Subject: yes, part of FORM properties
While you have a plain form open, click on “Form Properties” and look at the bottom on the 4th tab… Right there - Themes… with the default “Use database setting” as an option…
Gotta love it!
Subject: That isn’t themes, it’s themes 
Specifically, that is not Xpages Themes, that is OS themes. Confusing, you bet.
Subject: Yup. There’s no real bridge between old and new design elements, though you can obviously have forms and XPages in the same database.
Subject: Then why do we have the option in Forms?
OK, then IBM shouldn’t be giving us theme definitions on our form properties… Domino knows I’m a form and not an XPage, so why in the world give me the option at the form property level to use themes?
Just griping… 
Meanwhile, I’ll go back to the old way of putting my css files on each form, etc.
Debbie