Here are two versions that explore this.
Using @jonathan's type of code example of changing properties in a symbol on symbol load will work for standard symbols and persistent symbols.
But if you make for example your navigation UI and then change it to a persistent symbol across scenes, the code will not run a second time. This is because the Persistent symbol will not load twice..
There are a few ways to adjust this and these are just two of the top of my head.
The first is the simplest and @jonathan has already pointed to, is to make the code run on scene load.
The extra bit will be code to determine the scene and then change accordingly. This is pretty simple.
PersistantSymbolOnSceneLoadChange.hype.zip (38.9 KB)
The second way is just as easy but would depend on your setup and if it is necessary. for example you have already made you navigation elements a standard symbol.
If your navigation is already a standard Symbol. You should be able to select it and make the selection a Persistent Symbol.
i.e a standard symbol inside a persistent symbol copied to all scenes.
The code run by the standard symbol (symbol load) will work for it across scenes.
StandardSymbolInsidePersistantSymbol.hype.zip (53.6 KB)
The code will also work from the on scene load instead of symbol load.
On scene load in most cases it seems would be the easiest option.
I hope this adds to what @jonathan has explained and not confused.