The default icon theme for Xubuntu is "elementary Xfce". There's a theme for JDownloader that matches the icon theme, giving the application a more native look. Let's see how to install it.
- Download the theme from here.
- Extract the "jd" directory, that is inside the compressed file you just downloaded, into the hidden folder in your home called jdownloader (
- On JDownloader go to Settings > User Interface, choose the Light(GTK) style and choose Elementary as the theme.
- After restarting JDownloader the theme is applied.