Use lighter icon and update asset

app/assets/images/bookmark-outline.svg

@@ -1 +1 @@
-<svg viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="m18.7 0h-13.4c-1.5 0-2.7 1.2-2.7 2.7v21.3l9.3-4 9.3 4v-21.3c0-1.5-1.2-2.7-2.7-2.7zm0 20-6.7-2.9-6.7 2.9v-17.3h13.3v17.3z"/></svg>
+<svg viewBox="0 0 52 52" xmlns="http://www.w3.org/2000/svg"><path d="m14.5 49.6c-1.4.8-3.3.3-4.1-1.1-.3-.5-.4-1-.4-1.5v-41c0-2.2 1.8-4 4-4h24c2.2 0 4 1.8 4 4v41c0 1.7-1.3 3-3 3s-1 0-1.5-.4l-11.5-6.6zm23.5-4.3v-39.3h-24v39.3l10.8-6.1c.8-.4 1.7-.4 2.5 0l10.8 6.1z" fill-rule="evenodd"/></svg>

app/views/filters/_settings.html.erb

@@ -38,7 +38,7 @@
       <% else %>
         <% filter_params = filter.as_params.transform_values { |v| v.respond_to?(:to_str) ? v.to_str : v } %>
         <%= button_to filters_path, method: :post, params: filter_params, class: "btn txt-x-small", form_class: "inline" do %>
-          <%= icon_tag "bookmark" %>
+          <%= icon_tag "bookmark-outline" %>
           <span class="for-screen-reader">Save filter</span>
         <% end %>
       <% end %>