app/assets/stylesheets/admin.scss

@@ -4,7 +4,8 @@ body#admin-panel {
   #wrapper {
     > header {
       background: $color-red-bright;
-      background: linear-gradient(35deg, $color-purple 0, $color-red-dark 100%);
+      background: linear-gradient(35deg, rgba(137,85,160,0.8) 0, rgba(153,12,14,0.9) 100%),
+                  url('/img/bg-1.jpg');
     }
   }
 

app/assets/stylesheets/layout.scss

@@ -9,8 +9,9 @@
     margin: 0 auto;
     padding: 4rem 0;
     text-align: center;
-    background: $color-blue;
-    background: linear-gradient(35deg, $color-purple 0, $color-blue 100%);
+    background: linear-gradient(35deg, rgba(137,85,160,0.8) 0, rgba(13,79,153,0.8) 100%),
+                url('/img/bg-1.jpg');
+    background-size: cover;
 
     @include media-max(small) {
       padding: 3rem 0;