All fields that are white during recording go grey during export to AVI (or any other video format). Please take a look at the attached screenshot. How to reproduce: create a new project with all default settings, record notepad and export to AVI.
As for the problem - adjusting player’s brightness and contrast actually showed the correct gamma in the resulting video but I still don’t understand why does it work like this now and why does absolutely the same project produces excellent result without any player adjustments in version 6.
Actually, this problem happens differently between graphics cards and media players. Since version 7, we introduce the Use JPEG color range… option, please make sure it is selected as in below screenshot: