use inverted style for remove buttons

app/views/admin/appearances/_form.html.haml

@@ -11,7 +11,7 @@
         = image_tag @appearance.header_logo_url, class: 'appearance-light-logo-preview'
         - if @appearance.persisted?
           %br
-          = link_to 'Remove header logo', header_logos_admin_appearances_path, data: { confirm: "Header logo will be removed. Are you sure?"}, method: :delete, class: "btn btn-remove btn-sm remove-logo"
+          = link_to 'Remove header logo', header_logos_admin_appearances_path, data: { confirm: "Header logo will be removed. Are you sure?"}, method: :delete, class: "btn btn-inverted btn-remove btn-sm remove-logo"
         %hr
       = f.hidden_field :header_logo_cache
       = f.file_field :header_logo, class: ""
@@ -38,7 +38,7 @@
         = image_tag @appearance.logo_url, class: 'appearance-logo-preview'
         - if @appearance.persisted?
           %br
-          = link_to 'Remove logo', logo_admin_appearances_path, data: { confirm: "Logo will be removed. Are you sure?"}, method: :delete, class: "btn btn-remove btn-sm remove-logo"
+          = link_to 'Remove logo', logo_admin_appearances_path, data: { confirm: "Logo will be removed. Are you sure?"}, method: :delete, class: "btn btn-inverted btn-remove btn-sm remove-logo"
         %hr
       = f.hidden_field :logo_cache
       = f.file_field :logo, class: ""
@@ -70,7 +70,7 @@
         .js-favicons{ data: { favicon: @appearance.favicon.favicon_main.url, status_overlays: Gitlab::Favicon.available_status_overlays } }
         - if @appearance.persisted?
           %br
-          = link_to 'Remove favicon', favicon_admin_appearances_path, data: { confirm: "Favicon will be removed. Are you sure?"}, method: :delete, class: "btn btn-remove btn-sm remove-logo"
+          = link_to 'Remove favicon', favicon_admin_appearances_path, data: { confirm: "Favicon will be removed. Are you sure?"}, method: :delete, class: "btn btn-inverted btn-remove btn-sm remove-logo"
         %hr
       = f.hidden_field :favicon_cache
       = f.file_field :favicon, class: ''