Inserted window has a red sill in plan view

[Aussie John]

Anyone have any idea where I should look to change the archicad window which shows red in plan.
A window I developed about 20 years ago works fine!!

please see screens shots

[Kristian Bursell]

it looks like a graphic override or renovation filter.
One of my clients was getting the same colour on the background fill of my ceiling object, and it turned out that they had it set to "existing" in the "Renovation Status" under "Classification and Properties" in the object settings, and this was the colour set to define existing elements in the Renovation Filter.