Update partial that ovverides Bootstrap variables

Check and find right variables partial that is using to ovveride the
Bootstrap default variables. This is necessary to update colors of
buttons and minor components, later.

backend/app/assets/stylesheets/spree/backend/_bootstrap_custom.scss

@@ -7,10 +7,13 @@
 //
 // Grayscale and brand colors for use across Bootstrap.
 
-$blue:   $color-3 !default;
+$primary:          $color-2 !default;
+$secondary:        #C7CDD5 !default;
+
+$blue:   $color-2 !default;
 $red:    $color-5 !default;
 $orange: $color-6 !default;
-$green:  $color-2 !default;
+$green:  $color-success !default;
 
 // Body
 //
@@ -64,7 +67,8 @@ $border-radius:          3px !default;
 
 // Forms
 
-$input-color:                    $color-3 !default;
+$input-color:                    $color-4 !default;
+$input-placeholder-color:        $color-8 !default;
 $input-border-color:             $color-border !default;
 $input-focus-border-color:       $color-2 !default;
 
@@ -75,9 +79,9 @@ $custom-select-focus-border-color: $input-focus-border-color !default;
 // Dropdown menu container and contents.
 
 $dropdown-link-hover-color:      #fff !default;
-$dropdown-link-hover-bg:         $color-3 !default;
+$dropdown-link-hover-bg:         $color-2 !default;
 
 // Breadcrumbs
 
 $breadcrumb-bg:                 transparent !default;
-$breadcrumb-active-color:       $color-4 !default;
+$breadcrumb-active-color:       $color-2 !default;

backend/app/assets/stylesheets/spree/backend/globals/_variables_override.scss

@@ -4,6 +4,4 @@
   To set your own colors, sizes or fonts just override this 
   file in your application and set variables according to
   globals/_variables.scss file.
-  --------------------------------------------------------- */
-$primary:          #3D76F1 !default;
-$secondary:        #C7CDD5 !default;
+  --------------------------------------------------------- */