ColorCompletion.ps1

Function ColorCompletion {
    param($commandName, $parameterName, $wordToComplete, $commandAst, $fakeBoundParameter)
    [System.Drawing.KnownColor].GetFields() | Where-Object {$_.IsStatic -and $_.name -like "$wordToComplete*" } |
        Sort-Object name | ForEach-Object {New-CompletionResult $_.name $_.name
    }
}

if (Get-Command -Name register-argumentCompleter -ErrorAction SilentlyContinue) {
    Register-ArgumentCompleter -CommandName Export-Excel               -ParameterName TitleBackgroundColor -ScriptBlock $Function:ColorCompletion
    Register-ArgumentCompleter -CommandName Add-ConditionalFormatting  -ParameterName ForeGroundColor      -ScriptBlock $Function:ColorCompletion
    Register-ArgumentCompleter -CommandName Add-ConditionalFormatting  -ParameterName DataBarColor         -ScriptBlock $Function:ColorCompletion
    Register-ArgumentCompleter -CommandName Add-ConditionalFormatting  -ParameterName BackgroundColor      -ScriptBlock $Function:ColorCompletion
    Register-ArgumentCompleter -CommandName Set-Format                 -ParameterName FontColor            -ScriptBlock $Function:ColorCompletion
    Register-ArgumentCompleter -CommandName Set-Format                 -ParameterName BackgroundColor      -ScriptBlock $Function:ColorCompletion
    Register-ArgumentCompleter -CommandName Set-Format                 -ParameterName PatternColor         -ScriptBlock $Function:ColorCompletion
}