It could be great to have the capability to manage the color and the transparency of route layer.
For example: I have a personnal basemap and I would like to see my coloured layer under the route.
In ArcGIS Pro, Select the Route layer under Drawing Order in Contents Pane. Go to 'Appearance' tab and change the Swipe settings under 'Effects' group to change the transparency of your Route layer.
Hope this helps.
I'm knowing this solution, but this one doesn't modify the transparency into Navigator, but only in ArcGIS pro.
Retrieving data ...