The default theme for the PowerShell ISE is very boring, lets spice it up with a new theme. There is a great repository with PowerShell ISE themes located on GitHub. Scroll down on the GitHub page to see the different themes in action.
To import the themes into the PowerShell ISE:
Click on Tools > Options > Manage Themes > Import.
You can download all the themes and import the one you really like 🙂