Use aliases for the colors

Author: simurai

src/labels/diffstat.scss

@@ -20,13 +20,13 @@
 }
 
 .diffstat-block-deleted {
-  background-color: $red-600;
+  background-color: $bg-diffstat-deleted;
 }
 
 .diffstat-block-added {
   background-color: $bg-diffstat-added;
 }
 
 .diffstat-block-neutral {
-  background-color: $gray-300;
+  background-color: $bg-diffstat-neutral;
 }

src/support/variables/misc.scss

@@ -37,3 +37,8 @@ $max_tab_size: 12;
 $form-control-shadow: inset 0 1px 2px rgba($black, 0.075);
 $btn-input-focus-shadow: 0 0 0 0.2em rgba($blue, 0.3);
 $btn-active-shadow: inset 0 0.15em 0.3em $black-fade-15;
+
+// diffstat
+$bg-diffstat-added: darken($green-400, 5%);
+$bg-diffstat-deleted: $red-600;
+$bg-diffstat-neutral: $gray-300;