In v5, you can import the settings ini file from v4 (NOT the display mode ini file) to set these “globally”. These settings will be used for all display modes. You can then go in into View > Display Modes and override these global settings per display mode if that is what you want.
I don’t use toolbars but it looks like you are after a combination of Window color 1 and Window color 2 for the first part of the question and I would think that you need to go into the settings of the Windows operating system to change the blue theme…