Can Plex background be changed from black?



Plex is installed on Synology NAS and accessed via Windows 10.1 Plex app and via Chrome webpage. Plex background is black for all screens and I can't read the text. Black is a poor colour to choose for background if text needs to be read. Can't find any preference setting anywhere to change background to something plain but readable. Any guidance would be much appreciated, because if not possible will have to abandon.