the slide bar for navigation is not high enough contrast to use easily. How do I change the view to make it easier to see navigation bars
You can choose another icon set in the Settings, and/or even you can download more icon sets from the Extension and Templates site. Just install it as a normal Extension. The installed icon set will be appeared in the Settings after (full) restarting the LibreOffice.
The settings is available from the menu:
Tools - Options - LibreOffice - View - Icon Style
There are also Options for high contrast appearance you could try in
Tools - Options - LibreOffice - Accessibility