diff --git a/wagtail/wagtailadmin/static_src/wagtailadmin/scss/components/main-nav.scss b/wagtail/wagtailadmin/static_src/wagtailadmin/scss/components/main-nav.scss
index 13087e18d..38c1ef0c9 100644
--- a/wagtail/wagtailadmin/static_src/wagtailadmin/scss/components/main-nav.scss
+++ b/wagtail/wagtailadmin/static_src/wagtailadmin/scss/components/main-nav.scss
@@ -3,12 +3,15 @@ $submenu-color:darken($color-grey-1, 5%);
 
 .nav-wrapper{
     position: relative;
-    background: $color-grey-1;
     margin-left: -$menu-width;
     width: $menu-width;
     float: left;
     height:100%;
     min-height:800px;
+    background: $color-grey-1;
+    .inner {
+      background: $color-grey-1;
+    }
 }
     #nav-toggle{
         left: $mobile-nice-padding;
@@ -278,7 +281,6 @@ body.explorer-open {
 
         .footer{
             padding-top:1em;
-            background-color:$color-grey-1;
             position:fixed;
             width:$menu-width - 7;
             bottom:0;
@@ -404,7 +406,7 @@ body.explorer-open {
 }
 
 /* Media query hacks to detect IE10+ which doesn't support 3d transform of static elements and needs a fallback */
-@media all and (-ms-high-contrast: none), 
+@media all and (-ms-high-contrast: none),
        all and (-ms-high-contrast: active) {
     .wrapper{
         @include transition(left 0.2s ease);
@@ -414,7 +416,7 @@ body.explorer-open {
         .wrapper{
             @include transform(none);
             left:$menu-width;
-            position:relative        
+            position:relative
         }
     }
     body.explorer-open {
@@ -428,7 +430,7 @@ body.explorer-open {
     }
 }
 
-@media all and (min-width: $breakpoint-mobile) and (-ms-high-contrast: none), 
+@media all and (min-width: $breakpoint-mobile) and (-ms-high-contrast: none),
        all and (min-width: $breakpoint-mobile) and (-ms-high-contrast: active){
     body.explorer-open{
         .wrapper {