Die Werkzeugleiste wird nur in graustufen angezeigt und nicht in farbe. Wie kann ich das beheben.

What version of photoshop elements and operating system do you have?

If it's photoshop elements 2024 then yes Adobe removed all the color from tools panel.

Can you post a screenshot of what your seeing?

(sorry Greg S i didn't see your response before posting)

I assume you have just upgraded to Elements 2024.  The UI designers have removed all color from the tool panel and there is no way to change it.  Like you, I wish they had not done this.  This new UI was intended to address the many complaints about the lack of a dark interface.   And while color has been removed from the toolbar, color has been added in other buttons which I find to be inconsistent.  This just shows that you can't please all of the people all of the time.   😉

Try this:

Restore default preferences
Preference settings control how Photoshop Elements Editor displays images, cursors, and transparencies, saves files, uses plug‑ins and scratch disks, and so on. If the application exhibits unexpected behavior, the preferences file could be damaged. You can restore all preferences to their defaults.

Note: Deleting the preferences file is an action that cannot be undone.

Do one of the following:

Press and hold Alt+Control+Shift (Mac: Option+Command+Shift) immediately after Photoshop Elements begins launching. Click Yes to delete the Adobe Photoshop Elements settings file.
Go to Edit > Preferences (Mac: Photoshop Elements > Preferences > General), click the Reset Preferences on next launch button, and then click OK. When you restart Adobe Photoshop Elements, all preferences are reset to default settings.
A new preferences file is created the next time you start Photoshop Elements Editor. For information on a specific preference option, search for the preference name in Help.

from here:

https://helpx.adobe.com/photoshop-elements/kb/preference-file-locations-photoshop-elements.html