Hi Norm,
the page was set as PHP and I was unable to get any global colour to work in preview mode on any browser.
It was displaying correctly in Blocs which was confusing.
I have Firefox set to keep no cache for these tricky items and it had the same problem as Safari and Chrome.
All attempts to fix, restart of Blocs and Mac did not fix the problem.
The problem did eventually go but I’m unsure how/why?
I’ll close this one out as I’m not able to reproduce now