Is there a way to specify a font color when using write-output

This way:

function Green
{
    process { Write-Host $_ -ForegroundColor Green }
}

function Red
{
    process { Write-Host $_ -ForegroundColor Red }
}

Write-Output "this is a test" | Green
Write-Output "this is a test" | Red

I had the same problem, so I share my solution which I think works quite well:

Write-ColorOutput "Hello" Green Black -NoNewLine
Write-ColorOutput " World" Red

This is the Cmdlet to use it

function Write-ColorOutput
{
    [CmdletBinding()]
    Param(
         [Parameter(Mandatory=$False,Position=1,ValueFromPipeline=$True,ValueFromPipelinebyPropertyName=$True)][Object] $Object,
         [Parameter(Mandatory=$False,Position=2,ValueFromPipeline=$True,ValueFromPipelinebyPropertyName=$True)][ConsoleColor] $ForegroundColor,
         [Parameter(Mandatory=$False,Position=3,ValueFromPipeline=$True,ValueFromPipelinebyPropertyName=$True)][ConsoleColor] $BackgroundColor,
         [Switch]$NoNewline
    )    

    # Save previous colors
    $previousForegroundColor = $host.UI.RawUI.ForegroundColor
    $previousBackgroundColor = $host.UI.RawUI.BackgroundColor

    # Set BackgroundColor if available
    if($BackgroundColor -ne $null)
    { 
       $host.UI.RawUI.BackgroundColor = $BackgroundColor
    }

    # Set $ForegroundColor if available
    if($ForegroundColor -ne $null)
    {
        $host.UI.RawUI.ForegroundColor = $ForegroundColor
    }

    # Always write (if we want just a NewLine)
    if($Object -eq $null)
    {
        $Object = ""
    }

    if($NoNewline)
    {
        [Console]::Write($Object)
    }
    else
    {
        Write-Output $Object
    }

    # Restore previous colors
    $host.UI.RawUI.ForegroundColor = $previousForegroundColor
    $host.UI.RawUI.BackgroundColor = $previousBackgroundColor
}

Separate the results on the pipeline from the status messages in the console.

E.g., use a function like this in your script:

function write-status( $status ){
   $status | write-host -fore green -back red;  #send a status msg to the console
   $status | write-output; #send a status object down the pipe
}

I would also recommend you use one of the following cmdlets over write-host for outputting status messages from your scripts:

• write-debug
• write-error
• write-verbose
• write-warning

The appearance of these status messages will vary depending on the cmdlet used. In addition, the user can disable specific levels of status using the $(warning|error|verbose|debug)preference variables, or capture specific status messages using the -(warning|error|verbose|debug)variable common cmdlet parameters.

I have tried this extra function and it basically works fine:

function Write-ColorOutput($ForegroundColor)
{
    # save the current color
    $fc = $host.UI.RawUI.ForegroundColor

    # set the new color
    $host.UI.RawUI.ForegroundColor = $ForegroundColor

    # output
    if ($args) {
        Write-Output $args
    }
    else {
        $input | Write-Output
    }

    # restore the original color
    $host.UI.RawUI.ForegroundColor = $fc
}

# test
Write-ColorOutput red (ls)
Write-ColorOutput green (ls)
ls | Write-ColorOutput yellow

The result of this particular test is a little bit funny though: we really get lines in red, green and yellow but the table header is in red, i.e. the color of the the first call of the function.