The default text/icon color in my top panel has changed from white to a very dark grey, making my menus virtually unreadable against the black of the Ambiance theme. This includes even the login screen menu. I used Gnome Tweak to change the theme to Adwaita, but while some text has gone light grey (e.g. Date/Time), the login menu text remains dark grey, as do most icons (e.g. dropbox, wireless, battery indicator...) in the top panel after I log in. I tried deleting the top panel altogether but the option of deleting under Super + Alt + Right Click is blocked off. I tried running a panel from the terminal, but it came up in strange colors too, plus icons had moved around and some parts of the panel were opaque and other parts transparent. Deleting the panel wouldn't solve the basic problem anyway, as my login menu would still be very dark grey and unreadable against the default (black) Ambiance background. I would like to keep Ambiance but I want to reset the color to default (white) again. Can anyone help me?