Use theme

lib/utils/ui_utils.dart

@@ -36,31 +36,34 @@ Widget buildErrorCard(String message,
     {List<Widget> actions, bool hide = false}) {
   if (hide) return Container();
 
-  return Card(
-    elevation: 2.0,
-    color: Colors.red,
-    child: Padding(
-      padding: const EdgeInsets.all(8.0),
-      child: Row(
-        children: <Widget>[
-          Padding(
-            padding: const EdgeInsets.only(right: 8.0),
-            child: Icon(
-              Icons.error,
-              color: Colors.white,
+  return Theme(
+    data:
+        ThemeData(textTheme: TextTheme(body1: TextStyle(color: Colors.white))),
+    child: Card(
+      elevation: 2.0,
+      color: Colors.red,
+      child: Padding(
+        padding: const EdgeInsets.all(8.0),
+        child: Row(
+          children: <Widget>[
+            Padding(
+              padding: const EdgeInsets.only(right: 8.0),
+              child: Icon(
+                Icons.error,
+                color: Colors.white,
+              ),
             ),
-          ),
-          Flexible(
-            child: Text(
-              message,
-              style: TextStyle(color: Colors.white),
-              maxLines: null,
+            Flexible(
+              child: Text(
+                message,
+                maxLines: null,
+              ),
             ),
-          ),
-          Row(
-            children: actions == null ? <Widget>[] : actions,
-          )
-        ],
+            Row(
+              children: actions == null ? <Widget>[] : actions,
+            )
+          ],
+        ),
       ),
     ),
   );