Android (and Samsung) has the ability to change a theme across the entire operating system, so that the background images and colors are standard through the entire phone interface. Textra, however, does not support the implementation of the system theme. The app really needs the ability to do this, as it has so many other great features, but the UI is quickly getting boring and outdated compared to other apps on the market. Please compare to the Samsung Messages App when a Samsung theme is applied. I would switch over, but that app does not support iOS emojis and no gif support.