In a Gen 8.6 model there are three options for Window Video Properties at Business System and Windows Navigation Diagram levels i.e. Foreground, Background, Font.
There is a Color dropdown in the Font dialog box but after changing it from Black to Red it has no effect and Black is still used.
Gen Workstation Toolset
The Font dialog box has a Color dropdown which has no effect i.e. it can be changed and saved but when the dialog is reopened the change has been reverted to Black.
The Color property can only be changed in the Foreground & Background dialogs.