Fix ChangeColorsHandler to support the new material palette

src/Web/Features/Contents/Handlers/CreateCreator.cs

@@ -39,11 +39,24 @@ public sealed class CreateCreatorHandler(
         CancellationToken ct)
     {
         await context.Creators.AddAsync(
-            new()
+            new Creator
             {
                 Id = req.CreatorId,
                 CreatedBy = User.GetUserId(),
-                Name = req.Name
+                Name = req.Name,
+                Colors =
+                {
+                    Primary = "#6200EE",
+                    OnPrimary = "#FFFFFF",
+                    Secondary = "#03DAC6",
+                    OnSecondary = "#000000",
+                    Surface = "#FFFFFF",
+                    OnSurface = "#000000",
+                    Error = "#B00020",
+                    OnError = "#FFFFFF",
+                    Background = "#FFFFFF",
+                    OnBackground = "#000000",
+                }
             },
             ct);