I see your point about a more modern design of the toolbar icons has somewhat decreased the readability. Not less if the screen
contrast is poor. Since prebuilt icons are used there is no obvious way to change details for the toolbars. It's though possible to change the size if that could help. >> Tools->User Interface->"User interface scale factor". Change size using the slider.
For the active route consol it's more or less the same. The font size is controlled by Tools->User Interface->Fonts->Console legend/value.
The background is not able to change but try to change font color to white for more contrast. ("Black" is default but is of course changed to green by the program code.)