issue fix

Billing.Shared/Helper.cs

@@ -1,4 +1,5 @@
 using Billing.Models;
+using Billing.Themes;
 using Billing.UI;
 using Billing.Views;
 using System;
@@ -83,9 +84,13 @@ namespace Billing
 
         public static UIBill WrapBill(Bill b)
         {
+            var category = App.Categories.FirstOrDefault(c => c.Id == b.CategoryId);
             return new UIBill(b)
             {
-                Icon = App.Categories.FirstOrDefault(c => c.Id == b.CategoryId)?.Icon ?? Definition.DefaultIcon,
+                Icon = category?.Icon ?? Definition.DefaultIcon,
+                TintColor = category?.TintColor.IsTransparent() == false ?
+                    category.TintColor.ToColor() :
+                    BaseTheme.CurrentPrimaryColor,
                 Name = b.Name,
                 DateCreation = b.CreateTime,
                 Amount = b.Amount,