Improved look of mentions a tad.

assets/less/mio/classes/comment.less

@@ -21,6 +21,16 @@
         margin-bottom: 3px;
     }
 
+    &__mention {
+        color: inherit;
+        text-decoration: none;
+        font-weight: 700;
+
+        &:hover {
+            text-decoration: underline;
+        }
+    }
+
     &__actions {
         list-style: none;
         display: flex;

src/Users/user.php

@@ -55,13 +55,6 @@ function user_id_from_username(string $username): int
     return $getId->execute() ? (int)$getId->fetchColumn() : 0;
 }
 
-function user_username_from_id(int $userId): string
-{
-    $getId = Database::prepare('SELECT `username` FROM `msz_users` WHERE `user_id` = :user_id');
-    $getId->bindValue('user_id', $userId);
-    return $getId->execute() ? (string)$getId->fetchColumn() : 'deleted';
-}
-
 define('MSZ_USER_AVATAR_FORMAT', '%d.msz');
 
 function user_avatar_delete(int $userId): void

src/comments.php

@@ -39,7 +39,32 @@ function comments_parse_for_store(string $text): string
 function comments_parse_for_display(string $text): string
 {
     return preg_replace_callback(MSZ_COMMENTS_MARKUP_USER_ID, function ($matches) {
-        return '<a href="/profile.php?u=' . $matches[1] . '">@' .  user_username_from_id($matches[1]) . '</a>';
+        $getInfo = Database::prepare('
+            SELECT
+                u.`user_id`, u.`username`,
+                COALESCE(u.`user_colour`, r.`role_colour`) as `user_colour`
+            FROM `msz_users` as u
+            LEFT JOIN `msz_roles` as r
+            ON u.`display_role` = r.`role_id`
+            WHERE `user_id` = :user_id
+        ');
+        $getInfo->bindValue('user_id', $matches[1]);
+        $info = $getInfo->execute() ? $getInfo->fetch(PDO::FETCH_ASSOC) : [];
+
+        if (!$info) {
+            return $matches[0];
+        }
+
+        return '<a href="/profile.php?u='
+            . $info['user_id']
+            . '" class="comment__mention" style="'
+            . html_colour($info['user_colour'], [
+                'color' => '%s',
+                'text-shadow' => '0 0 5px %s',
+            ])
+            . '">@'
+            .  $info['username']
+            . '</a>';
     }, $text);
 }