implemented the color icon for theme spring

src/client/styles/scss/theme/spring.scss

@@ -155,4 +155,15 @@ html[dark] {
       }
     }
   }
+
+  /*
+  * GROWI user page
+  */
+  .grw-page-list-m {
+    .grw-page-list-title-m {
+      svg {
+        fill: $subthemecolor;
+      }
+    }
+  }
 }