diff --git a/org-base.sass b/org-base.sass
index 3a37c1c..7735093 100644
--- a/org-base.sass
+++ b/org-base.sass
@@ -5,6 +5,7 @@
 @include mixins-basic.remove-section-number(h5)
 @include mixins-basic.remove-section-number(h2)
 @include mixins-basic.remove-section-number(h4)
+@include mixins-basic.remove-section-number(h6)
 
 /*
  * NOTE
@@ -112,7 +113,10 @@ div#postamble
 
 .outline-5
   margin-bottom: .2em
-  margin-left: .7em
+  margin-left: 1em
+
+.outline-6
+  margin-left: 1.2em
 
   ul
     padding-top: 0
diff --git a/themes/sienna-elegance.sass b/themes/sienna-elegance.sass
index e59e75d..536c32a 100644
--- a/themes/sienna-elegance.sass
+++ b/themes/sienna-elegance.sass
@@ -62,6 +62,8 @@ $default-header-colors: map.set($default-header-colors, h1, $primary-color)
 $default-header-colors: map.set($default-header-colors, h2, $secondary-color)
 $default-header-colors: map.set($default-header-colors, h3, $tertiary-color)
 $default-header-colors: map.set($default-header-colors, h4, $quaternary-color)
+$default-header-colors: map.set($default-header-colors, h5, $tertiary-color)
+$default-header-colors: map.set($default-header-colors, h6, $quinary-color)
 
 // Initialize empty maps
 $default-header-margins-sides: ()