Hmmm...reused an old monitor profile and my color is back to normal. Maybe my calibator is off....
Thanks for your responses everyone.
Suspected as much that this was a faulty profile issue. Do not bother with Windows Photos it is
NOT colour managed and will give strange results
As I had prepared this before your last post it may be of interest. Your image showing in PS, Firefox showing 'correct' colour (left hand side) and what happens when brought into Photos. You may prefer the colour of the Photos version but be aware that this is not a correct representation of your data due to no colour managment
Additionally you should check that Windows is applying your monitor profile correctly as in the bottom right image