Can we globally style elements in Ionic 4?

I am porting my Ionic 3 application to Ionic 4.

In the Ionic 3 version, I set styles of quite a few of the elements globally, so there is only ever one place to change them all should the need arise.

For example, in Ionic 3 , in my app.scss I would have…

.toolbar-background{
      background-color: color($colors, secondary-lite);
    }

}
etc

Can I do something similar in Ionic 4?

Also (if possible), where would I put such global styles…
global.scss, variables.scss, somewhere else?

I know I can change the toolbar color, as in the following…

<ion-header>
  <ion-toolbar color="primary">
    <ion-title color='light'>

But is there a way to just do this to every ion-toolbar without having to add the color attribute to each one?

Thanks in advance

I have found a way to do it. Not sure if this is the correct, but seems like the right place…?

In my variables.sccs, I have put the following…

  ion-toolbar{
    --background : var(--ion-color-primary);
    --color : var(--ion-color-light);
  }

And now this seems to be picked up everywhere. In my case, I want them (for now) to “follow” other variables (hence the var(--ion-color-primary); etc).

Gives the exact results I am after.