When you choose the Light or
Hybrid theme as the default appliance theme, the login page appears with a white background. A dark background is applied when the
Dark theme is applied as the default appliance theme. The color of the login screen always reflects the configured appliance theme, not the theme associated with your user account. For example, if you choose the Dark theme in the Administration Console, this theme becomes associated with your user account and is applied each time you log in. However if the appliance uses the Light theme by default, your login screen always appears with a white background. After a successful login, the Dark theme is applied.