Hi Joan,
Welcome to Microsoft Community.
It sounds like your Surface Laptop 7th is experiencing a display profile or driver-related issue. Since the colors return to normal when switching between displays, the issue is likely software-related rather than a hardware failure. Here are some steps to troubleshoot and possibly fix the problem:
- You can quickly check the health of your Surface drivers and firmware using the Surface app.
- In the Surface app, expand Help & support to check the update status.
- If there are updates available, select the Check for updates button to open Windows Update and install the available updates.
- Refresh the screen with keyboard shortcuts
If the device has power, try refreshing the screen with keyboard shortcuts. Connect your Surface to a keyboard, then press the Windows logo key + Ctrl + Shift + B.
- Manually update Surface drivers and firmware: Download drivers and firmware for Surface - Microsoft Support
- Safe Mode, which starts Windows in a limited state, where only the bare essentials services and drivers are started. If a problem doesn't reappear when you start in safe mode, you can eliminate the default settings, basic device drivers, and services as possible causes. Windows startup settings - Microsoft Support
- Reset Surface If you’re still having a problem with your display, try resetting your Surface. To learn how, see Restore or reset Surface for Windows and follow the recommended steps, or see create and use a USB recovery drive to reset your device to factory settings and drivers.
I hope this helps. If there is anything not clear, please do not hesitate to let me know.
Your Sincerely
Hahn. W - MSFT | Microsoft Community Support Specialist