>:( Can't get this to work -
echo ' <tr class=', $message['alternate'] == 0 ? 'windowbg' : 'windowbg2' ,'>';
Where does $message['alternate'] come from?
From Sources/Display.php::prepareDisplayContext()
'alternate' => $counter % 2,
Its just a shortcut to get a series of 0 and 1 for every message been displayed. $counter been the number assigned to the message while been retrieved.

Am modifying the comment section of a gallery mod, so it doesn't connect to
/Sources/Display.php. Guess I'll use yet another workaround -
if ($message['alternate'] == 0)
$message['alternate'] = 1;
elseif ($message['alternate'] == 1)
$message['alternate'] = 0;
It really depends on what you're going to do, I just answered your question.
There are multiple ways to get an alternative, the simpliest and easiest would be to add your own $counter var.
Assuming you have an array of messages:
$myOwnCounter = 0;
foreach ($myMessages as $message)
{
$myOwnCounter++;
$cssBacjground= ($myOwnCounter % 2 == 0) ? 'white': 'black';
// Use $cssBackground
}
Just trying to alternate the bg between windowbg and windowbg2, as in display template. It currently has this -
echo '<tr class="windowbg">';
Will tinker with your counter code. Thanks.