diff --git a/phpBB/phpbb/textformatter/s9e/factory.php b/phpBB/phpbb/textformatter/s9e/factory.php
index 56b98e079f..58c1f2f16d 100644
--- a/phpBB/phpbb/textformatter/s9e/factory.php
+++ b/phpBB/phpbb/textformatter/s9e/factory.php
@@ -87,7 +87,6 @@ class factory implements \phpbb\textformatter\cache_interface
 		'mention' =>
 			"[MENTION={PARSE=/^(?<type>[ug]):(?<id>\d+)$/}
 				profile_url={URL;optional;postFilter=#false}
-				color={COLOR;optional}
 			]{TEXT}[/MENTION]",
 		'quote' =>
 			"[QUOTE
@@ -136,9 +135,6 @@ class factory implements \phpbb\textformatter\cache_interface
 			<xsl:when test="@profile_url">
 				<a class="mention">
 					<xsl:attribute name="href"><xsl:value-of select="@profile_url"/></xsl:attribute>
-					<xsl:if test="@color">
-						<xsl:attribute name="style">color: #<xsl:value-of select="@color"/>;</xsl:attribute>
-					</xsl:if>
 					<xsl:apply-templates/>
 				</a>
 			</xsl:when>
diff --git a/phpBB/phpbb/textformatter/s9e/mention_helper.php b/phpBB/phpbb/textformatter/s9e/mention_helper.php
index bd641b8b24..e7b58f0b81 100644
--- a/phpBB/phpbb/textformatter/s9e/mention_helper.php
+++ b/phpBB/phpbb/textformatter/s9e/mention_helper.php
@@ -42,11 +42,6 @@ class mention_helper
 	 */
 	protected $group_profile_url;
 
-	/**
-	 * @var array Array of users' and groups' colours for each cached ID
-	 */
-	protected $cached_colours = [];
-
 	/**
 	 * @var array Array of group IDs allowed to be mentioned by current user
 	 */
@@ -70,63 +65,6 @@ class mention_helper
 		$this->group_profile_url = append_sid($root_path . 'memberlist.' . $php_ext, 'mode=group&g={ID}', false);
 	}
 
-	/**
-	 * Returns SQL query data for colour SELECT request
-	 *
-	 * @param string $type Name type ('u' for users, 'g' for groups)
-	 * @return array Array of SQL SELECT query data for extracting colours for names
-	 */
-	protected function get_colours_sql($type)
-	{
-		switch ($type)
-		{
-			default:
-			case 'u':
-				return [
-					'SELECT' => 'u.user_colour as colour, u.user_id as id',
-					'FROM'   => [
-						USERS_TABLE => 'u',
-					],
-					'WHERE'  => $this->db->sql_in_set('u.user_type', [USER_NORMAL, USER_FOUNDER]),
-				];
-			case 'g':
-				return [
-					'SELECT' => 'g.group_colour as colour, g.group_id as id',
-					'FROM'   => [
-						GROUPS_TABLE => 'g',
-					],
-				];
-		}
-	}
-
-	/**
-	 * Caches colours of users and groups
-	 */
-	protected function cache_colours()
-	{
-		if (count($this->cached_colours) > 0)
-		{
-			return;
-		}
-
-		$types = ['u', 'g'];
-
-		foreach ($types as $type)
-		{
-			$this->cached_colours[$type] = [];
-
-			$query = $this->db->sql_build_query('SELECT', $this->get_colours_sql($type));
-			$result = $this->db->sql_query($query, 300);
-
-			while ($row = $this->db->sql_fetchrow($result))
-			{
-				$this->cached_colours[$type][$row['id']] = $row['colour'];
-			}
-
-			$this->db->sql_freeresult($result);
-		}
-	}
-
 	/**
 	 * Inject dynamic metadata into MENTION tags in given XML
 	 *
@@ -140,8 +78,6 @@ class mention_helper
 			'g' => $this->group_profile_url,
 		];
 
-		$this->cache_colours();
-
 		return TextFormatterUtils::replaceAttributes(
 			$xml,
 			'MENTION',
@@ -153,11 +89,6 @@ class mention_helper
 					$id = $attributes['id'];
 
 					$attributes['profile_url'] = str_replace('{ID}', $id, $profile_urls[$type]);
-
-					if (!empty($this->cached_colours[$type][$id]))
-					{
-						$attributes['color'] = $this->cached_colours[$type][$id];
-					}
 				}
 
 				return $attributes;
diff --git a/tests/text_formatter/s9e/fixtures/mention.xml b/tests/text_formatter/s9e/fixtures/mention.xml
index 9174029fd8..13553b1081 100644
--- a/tests/text_formatter/s9e/fixtures/mention.xml
+++ b/tests/text_formatter/s9e/fixtures/mention.xml
@@ -24,7 +24,7 @@
 			<value>3</value>
 			<value>Hidden group we are a member of</value>
 			<value>2</value>
-			<value>FF0000</value>
+			<value></value>
 			<value></value>
 		</row>
 	</table>
@@ -53,7 +53,7 @@
 			<value>test</value>
 			<value>0</value>
 			<value>0</value>
-			<value>00FF00</value>
+			<value></value>
 			<value></value>
 			<value></value>
 		</row>
diff --git a/tests/text_formatter/s9e/mention_helper_test.php b/tests/text_formatter/s9e/mention_helper_test.php
index 0cbb978649..0665cd3ce5 100644
--- a/tests/text_formatter/s9e/mention_helper_test.php
+++ b/tests/text_formatter/s9e/mention_helper_test.php
@@ -82,12 +82,10 @@ class mention_helper_test extends phpbb_database_test_case
 			[
 				'<r><MENTION id="3" type="u"><s>[mention=u:3]</s>test<e>[/mention]</e></MENTION></r>',
 				'mode=viewprofile&amp;u=3',
-				'color="00FF00"',
 			],
 			[
 				'<r><MENTION id="3" type="g"><s>[mention=g:3]</s>test<e>[/mention]</e></MENTION></r>',
 				'mode=group&amp;g=3',
-				'color="FF0000"',
 			],
 		];
 	}
@@ -95,11 +93,10 @@ class mention_helper_test extends phpbb_database_test_case
 	/**
 	 * @dataProvider inject_metadata_data
 	 */
-	public function test_inject_metadata($incoming_xml, $expected_profile_substring, $expected_colour)
+	public function test_inject_metadata($incoming_xml, $expected_profile_substring)
 	{
 		$result = $this->mention_helper->inject_metadata($incoming_xml);
 		$this->assertContains($expected_profile_substring, $result);
-		$this->assertContains($expected_colour, $result);
 	}
 
 	public function get_mentioned_user_ids_data()