I have a protected form so the user can only fill in form fields. However I want them to be able to change text size, colour, bold, italic etc.
I've tried "Limit formatting to a selection of styles" ticked and unticked. But either way ALL formatting options are greyed out.

I've even tried going into "Manage Styles" and making sure all the styles I want are unrestricted, but again this didn't seem to make any difference.

Any thoughts?
The ultimate goal is to stop any kind of spelling/grammer checks and stop the user from being able to turn them back on.

Have you tried creating a simple macro to open the format>fonts options only? This can then be added to the field by right clicking on it and selecting properties. Normally I would select the option to run macro on exit.

Hope this helps.