So as not to fill the brilliant thread Learn 2016 Theme Issues & Fixes Master List with my questions I will post them here.
Having decided that we will have to make a theme rather than just using the GUI branding options I wanted to do a proof of concept first on a 9.1 2018 Q4 CU3 dev server.
So I download the 2016 theme, uncompressed it, and edited themes.css and added
/* My Tests */ @import url("mods.css");
To it. Then I made the mods.css file and added
/*Top Frame Background Color / Background Image*/
to it. I believe that this should set the background colour of the top frame area. I then zipped up the files and went to
Administrator Panel> Brands and Themes >Theme and Palette Catalogue and clicked on Create theme and uploaded my zip file. In the preview the background colour of the top frame had been changed.
BUT when I then go to Brands and Themes > Customise Default Brand, I can choose my theme but after submitting it the top frame colour is not changed.
I'm guessing this is because when you add the theme you also have to choose the colour palette:
And the colour of the top frame is also set in the palette, and I was selecting the default palette.
Is this what is expected? So should I set the colours I'm able to in the GUI and then use a custom theme to set the colours and any other changes that are not possible in the GUI?
What I'm trying to do is to prove the approach works with some simple changes first before looking at something more complex.