bug(Toolbar): Defined background colors does not get applied with version 17.3.1

### Is this a regression?

- [X] Yes, this behavior used to work in the previous version

### The previous version in which this bug was not present was

16

### Description

If you go to the official `Angular Material` docs, and select component `Toolbar`, examples tab, you see in action the usage of toolbar with a color defined such as `primary` but you don't see any color applied to it.

If you open up any of the examples to Stackblitz, you can clearly see that any of the defined colors "warn", "primary", "accent" does not get applied in the toolbar property

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### Reproduction

StackBlitz link: https://stackblitz.com/edit/ga5498?file=src%2Fexample%2Ftoolbar-overview-example.html

Steps to reproduce:
1. Specify one of the colors predefined such as `warn`, `primary`, `accent` to the toolbar component

### Expected Behavior

If the developer specifies a color to a toolbar, either a predefined one or a custom one, then the color should take effect into the material component (e.g toolbar)

### Actual Behavior

Specifying any of the predefined colors does not get applied in the toolbar component

### Environment

- Angular: 17.3.0
- CDK/Material: 17.3.1
- Browser(s): Firefox 124.01 or Chrome 123.0.6312.86
- Operating System (e.g. Windows, macOS, Ubuntu): Linux Mint

Beginne mit der verlinkten StackBlitz-Reproduktion und ihrer Datei src/example/toolbar-overview-example.html und vergleiche anschließend das Verhalten der Toolbar über die gemeldeten Angular-Material-Versionen hinweg. Überprüfe die Farben primary, accent, warn und custom und ermittle den relevanten Projekteinstiegspunkt oder Test, bevor du etwas änderst. Als erledigt gilt die Aufgabe, wenn die Toolbar die angegebenen Farben anwendet und die Regression durch einen erfolgreichen Check abgedeckt ist.

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