New
#41
Ok, thanks, I thought that would be the case.
It's finally clicked as to what's happening - I dealt with this about 3 years ago!
When you restarted without the gpedit changes the existing theme (without your colour) is reapplied automatically. Hence you lost the colour on restart. Had you saved your current theme with the colour applied (which is what I did), then you would have retained the colours on restart.