Universal Dashboard is now a part of PowerShell Universal. This documentation is for reference to the v2 version of Universal Dashboard and is no longer maintained. PowerShell Universal Documentation can be found here.
Many controls offer the ability to change colors like the font and background colors. You can specify colors in a couple of different ways thanks to the DashboardColor class.
You can use any of the named colors found in the .NET Color struct.
New-UDCard -BackgroundColor 'red'
You can use standard HEX color specifiers.
New-UDCard -BackgroundColor "#E82C0C"
You can also include an alpha channel value.
New-UDCard -BackgroundColor "#E82C0CFA"
You can also specify colors using an ARGB value.
New-UDCard -BackgroundColor 16777215