I don’t think this is a major issue as it is functional at this moment in time. Perhaps the devs will look another time. Orange, brown same thing = terrain. :)
It seems to be depending on the light conditions wether the PFD ground section looks more brown or orange:
Source of the picture: https://pilotstories.net/airbus-a320-cockpit/
Lots of great pictures showing the differences depending on the loght conditions in the article I linked above.