
Kunena can't by default. It needs a little code tweaking.
The colors are defined by some weird calculation I let loose on the username.
On the table cell that holds this message I have this:
<?php
$colid = crc32( md5( 'ABCDEF'.$msg_username ) );
// set color of admin to grey (example userid 123, is probably 62)
if ( $fmessage->userid == 123 ) {
$colid = 1000000;
}
$colparts = array();
$colparts['r'] = substr( $colid, -6, 2 ) * 0.6 ;
$colparts['g'] = substr( $colid, -4, 2 ) * 0.8;
$colparts['b'] = substr( $colid, -2, 2 ) * 1;
$lightness = 3;
$colrgb = array();
$colrgb['r'] = ( 255 - round( 100 / $lightness ) ) + round( $colparts['r'] / $lightness );
$colrgb['g'] = ( 255 - round( 100 / $lightness ) ) + round( $colparts['g'] / $lightness );
$colrgb['b'] = ( 255 - round( 100 / $lightness ) ) + round( $colparts['b'] / $lightness );
?>
<td class = "fb-msgview-right fb-msgview-id_<?php echo $fmessage->userid; ?>" style="background-color: rgb( <?php echo $colrgb['r'].', '.$colrgb['g'].', '.$colrgb['b']; ?> );">