diff --git a/library/includes/bbcode.php b/library/includes/bbcode.php
index 9e34d8940..d2465c275 100644
--- a/library/includes/bbcode.php
+++ b/library/includes/bbcode.php
@@ -83,6 +83,23 @@ HTML;
 	<span class="post-hr">-</span>
 HTML;
 
+// Box
+    $bbcode_tpl['box_open'] = <<<HTML
+    <div class="post-box-default"><div class="post-box">
+HTML;
+
+    $bbcode_tpl['box_open_color'] = <<<HTML
+    <div class="post-box-default"><div class="post-box" style="border-color: $1; background-color: $2;">
+HTML;
+
+    $bbcode_tpl['box_open_color_single'] = <<<HTML
+    <div class="post-box-default"><div class="post-box" style="border-color: $1;">
+HTML;
+
+    $bbcode_tpl['box_close'] = <<<HTML
+    </div></div>
+HTML;
+
     array_deep($bbcode_tpl, 'bbcode_tpl_compact');
     return $bbcode_tpl;
 }
diff --git a/src/Legacy/BBCode.php b/src/Legacy/BBCode.php
index 1bd517c47..6c12d7602 100644
--- a/src/Legacy/BBCode.php
+++ b/src/Legacy/BBCode.php
@@ -97,6 +97,8 @@ class BBCode
             "#\[img=(left|right|center)\]($img_exp)\[/img\]\s*#isu" => $tpl['img_aligned'],
             "#\[email\]($email_exp)\[/email\]#isu" => '<a href="mailto:$1">$1</a>',
             "#\[qpost=([0-9]*)\]#isu" => '<u class="q-post">$1</u>',
+            '#\[box=(?:\s*[\'"])?([\#0-9a-zA-Z]+)(?:[\'"]\s*)?\]#isu' => $tpl['box_open_color_single'],
+            '#\[box=(?:\s*[\'"])?([\#0-9a-zA-Z]+)(?:[\'"]\s*)?,\s*[\'"]?([\#0-9a-zA-Z]+)[\'"]?\]#isu' => $tpl['box_open_color'],
         ];
 
         $this->str = [
@@ -127,8 +129,8 @@ class BBCode
             '[/sup]' => '</small></sup>',
             '[sub]' => '<sub><small>',
             '[/sub]' => '</small></sub>',
-            '[box]' => '<div class="post-box-default"><div class="post-box">',
-            '[/box]' => '</div></div>',
+            '[box]' => $tpl['box_open'],
+            '[/box]' => $tpl['box_close'],
             '[indent]' => '<div class="post-indent">',
             '[/indent]' => '</div>',
             '[del]' => '<span class="post-s">',
