If I have already completed my 20-page Elements website and later decide that I want to change the colour and size of all my H1 headings, how can I update every H1 tag across the entire site without changing any of the text content—only the style (colour and size)?
Sorry no…
Globals would change all to the same text - same size - same color
What I do:
Make one definitive page - check everything… double check
The copy it and insert new text header and content
I know it’s a little late for that….
Make the change in the theme studio.

Yes, this is possible. I don’t know exactly how you have things it set-up, but you can change Globals colours in the Theme Studio.
@dan On another note, has the theme studio been unlocked for creation / editing yet, rather than just overriding??
This is all part of the Store rollout as anyone will be able to create themes in app and share the with the community. We just have a little more work to do before making it public. More on that soon…
I’m sorry for giving you bad information. I didn’t know that it could be fixed. Please forgive my post.
Aha, slept on it one night. Brain started to function I understand this now.
Thank you.