<?php
use Microsoft\Graph\GraphServiceClient;
use Microsoft\Graph\Generated\Models\Message;
use Microsoft\Graph\Generated\Models\SingleValueLegacyExtendedProperty;
$graphServiceClient = new GraphServiceClient($tokenRequestContext, $scopes);
$requestBody = new Message();
$singleValueExtendedPropertiesSingleValueLegacyExtendedProperty1 = new SingleValueLegacyExtendedProperty();
$singleValueExtendedPropertiesSingleValueLegacyExtendedProperty1->setId('String {66f5a359-4659-4830-9070-00047ec6ac6e} Name Color');
$singleValueExtendedPropertiesSingleValueLegacyExtendedProperty1->setValue('Green');
$singleValueExtendedPropertiesArray []= $singleValueExtendedPropertiesSingleValueLegacyExtendedProperty1;
$requestBody->setSingleValueExtendedProperties($singleValueExtendedPropertiesArray);
$result = $graphServiceClient->me()->messages()->byMessageId('message-id')->patch($requestBody)->wait();