MatchInfo.format.ps1xml

<Configuration>
  <ViewDefinitions>
    <View>
      <Name>MatchInfo</Name>
       <ViewSelectedBy>
         <TypeName>Microsoft.PowerShell.Commands.MatchInfo</TypeName>
       </ViewSelectedBy>
       <CustomControl>
         <CustomEntries>
           <CustomEntry>
             <CustomItem>
                 <ExpressionBinding>
                   <ScriptBlock>
[string]$curDir = $pwd.Path 
if (!$host.UI.SupportsVirtualTerminal)
{
    $_.ToString($curDir)
    return
}

function FormatLine($matchInfo, [string]$line, [int]$lineNumber, [string]$displayPath, [string]$prefix, [switch]$isMatchLine)
{
    if ($isMatchLine)
    {
        $esc = [char]0x1b
        $matchStart = $matchInfo.Matches[0].Index
        $matchLength = $matchInfo.Matches[0].Length 
        $matchEnd = $matchStart + $matchLength 
        $line = $line.Substring(0, $matchStart) + "${esc}[93m" + $line.Substring($matchStart, $matchLength) + "${esc}[0m" + $line.Substring($matchEnd)
    }

    if ($matchInfo.Path -ne 'InputStream')
    {
        "{0}{1}:{2}:{3}" -f $prefix, $displayPath, $lineNumber, $line
    }
    else
    {
        "{0}{1}" -f $prefix, $line
    }
}

$displayPath = if ('' -eq $curDir) { $_.Path } else { $_.RelativePath($curDir) }
if ($null -eq $_.Context)
{
    FormatLine -MatchInfo $_ -Line $_.Line -LineNumber $_.LineNumber -DisplayPath $displayPath -Prefix "" -IsMatchLine
}
else
{
    $lines = . {
    $displayLineNumber = $_.LineNumber - $_.Context.DisplayPreContext.Length;
    foreach ($contextLine in $_.Context.DisplayPreContext)
    {
        FormatLine -MatchInfo $_ -Line $contextLine -LineNumber $displayLineNumber -DisplayPath $displayPath -Prefix "  "
        $displayLineNumber += 1
    }

    FormatLine -MatchInfo $_ -Line $_.Line -LineNumber $displayLineNumber -DisplayPath $displayPath -Prefix "> " -IsMatchLine
	  $displayLineNumber += 1

    foreach ($contextLine in $_.Context.DisplayPostContext)
    {
        FormatLine -MatchInfo $_ -Line $contextLine -LineNumber $displayLineNumber -DisplayPath $displayPath -Prefix "  "
        $displayLineNumber += 1
    }
    }

    $lines -join ([Environment]::Newline)
}
</ScriptBlock>
                 </ExpressionBinding>
               </CustomItem>
             </CustomEntry>
           </CustomEntries>
       </CustomControl>
    </View>
  </ViewDefinitions>
</Configuration>

Need a foreach on matches to handle the -AllMatches instead of just highlighting the first one

    if ($isMatchLine)
    {
        $esc = [char]0x1b
        for($i = $matchInfo.Matches.Count -1; $i -ge 0; $i--){
            $match = $matchInfo.Matches[$i]
            $Line = $Line.Insert($match.Index + $match.Length, "$esc[0m").Insert($match.Index, (Get-PSReadLineOption).EmphasisColor)
        }
    }