As this picture shows here are 3 apps, Edge (rear), Outlook and WhatsApp (front) and they all have differences - ow can I make them all the same, either, preferably as shown by Outlook in the middle, or alternatively as per Edge.
The only way to change the title bar seems to be to change the theme to Dark, for some reason I am not allowed to change the colour when using Light.
It is because Windows has to be in dark mode for it to be available. To make colors available in light mode:
go to settings-personalization- colors.
under 'choose your mode', change it to dark mode (this is temporary and it un-grays the option.)
Change 'show accent color on start and taskbar' to ON and change 'show accent color on title bar and windows borders' to ON.
scroll back up to 'choose your mode' change it to CUSTOM
set 'choose your windows default mode' to DARK
set 'choose your app mode' to LIGHT
The colors you see in Edge depend on your Edge theme.
Certain Windows apps will not reflect your system color choices.
I should have worded it differently. I should have said "the colors you see within Edge itself"
Most of my apps follow my respective chosen active and inactive title bar colors. However, Word (nor any part of Office)doesn't nor does explorer or settings. Control Panel does, but certain sections of Control panel when it's expanded do not.