If you have two or more virtual machines running simultaneously, the icons of all applications running in the virtual machines are usually present in the Dock. You can easily get confused to which virtual machine the app icon belongs. To distinguish one virtual machine from others, you can mark it with some color. Do one of the following:
Right-click a virtual machine in Control Center and choose the color you want at the bottom of the context menu.
Right-click your virtual machine in macOS (virtual machines are usually stored in the ~/Parallels folder) and choose the color you want from the context menu.
Note: This feature is not supported in the App Store edition of Parallels Desktop. For more information on the differences between the Standard and App Store editions, follow this link.
If you choose, for example, red, the Dock icons of this virtual machine applications will be marked with a red spot.
