diff --git a/Azaion.Annotator/DTO/AnnotationClass.cs b/Azaion.Annotator/DTO/AnnotationClass.cs
index df1fa19..e2bb115 100644
--- a/Azaion.Annotator/DTO/AnnotationClass.cs
+++ b/Azaion.Annotator/DTO/AnnotationClass.cs
@@ -4,12 +4,15 @@ using Azaion.Annotator.Extensions;
 
 namespace Azaion.Annotator.DTO;
 
-public class AnnotationClass(int id, string name = "")
+public class AnnotationClass
 {
-    public int Id { get; set; } = id;
+    public int Id { get; set; }
 
-    public string Name { get; set; } = name;
-    public Color Color { get; set; } = id.ToColor();
+    public string Name { get; set; }
+    public string ShortName { get; set; }
+
+    [JsonIgnore]
+    public Color Color => Id.ToColor();
 
     [JsonIgnore]
     public int ClassNumber => Id + 1;
diff --git a/Azaion.Annotator/DTO/AnnotationResult.cs b/Azaion.Annotator/DTO/AnnotationResult.cs
index aec26d8..c64e851 100644
--- a/Azaion.Annotator/DTO/AnnotationResult.cs
+++ b/Azaion.Annotator/DTO/AnnotationResult.cs
@@ -1,4 +1,5 @@
 using System.Windows.Media;
+using Azaion.Annotator.Extensions;
 using Newtonsoft.Json;
 
 namespace Azaion.Annotator.DTO;
@@ -23,38 +24,44 @@ public class AnnotationResult
     //For XAML Form
     public string TimeStr => $"{Time:h\\:mm\\:ss}";
 
+    private List<int>? _detectionClasses = null!;
+
+    //For Form
     [JsonIgnore]
-    //For XAML Form
     public string ClassName
     {
         get
         {
             if (Detections.Count == 0)
                 return "";
+            _detectionClasses ??= Detections.Select(x => x.ClassNumber).Distinct().ToList();
 
-            var groups = Detections.Select(x => x.ClassNumber).GroupBy(x => x).ToList();
-            return groups.Count > 1
-                ? string.Join(",", groups.Select(x => x.Key + 1))
-                : _config.AnnotationClassesDict[groups.FirstOrDefault().Key].Name;
+            return _detectionClasses.Count > 1
+                ? string.Join(", ", _detectionClasses.Select(x => _config.AnnotationClassesDict[x].ShortName))
+                : _config.AnnotationClassesDict[_detectionClasses.FirstOrDefault()].Name;
         }
     }
 
+
     [JsonIgnore]
-    //For XAML Form
-    public Color ClassColor
+    public Color ClassColor1 => GetAnnotationClass(0);
+    [JsonIgnore]
+    public Color ClassColor2 => GetAnnotationClass(1);
+    [JsonIgnore]
+    public Color ClassColor3 => GetAnnotationClass(2);
+    [JsonIgnore]
+    public Color ClassColor4 => GetAnnotationClass(3);
+
+    private Color GetAnnotationClass(int colorNumber)
     {
-        get
-        {
-            var defaultColor = (Color)ColorConverter.ConvertFromString("#404040");
-            if (Detections.Count == 0)
-                return defaultColor;
+        if (Detections.Count == 0)
+            return (-1).ToColor();
 
-            var groups = Detections.Select(x => x.ClassNumber).GroupBy(x => x).ToList();
+        _detectionClasses ??= Detections.Select(x => x.ClassNumber).Distinct().ToList();
 
-            return groups.Count > 1
-                ? defaultColor
-                : _config.AnnotationClassesDict[groups.FirstOrDefault().Key].Color;
-        }
+        return colorNumber >= _detectionClasses.Count
+            ? _config.AnnotationClassesDict[_detectionClasses.LastOrDefault()].Color
+            : _config.AnnotationClassesDict[_detectionClasses[colorNumber]].Color;
     }
 
 
diff --git a/Azaion.Annotator/DTO/Config.cs b/Azaion.Annotator/DTO/Config.cs
index 752fca5..206b8ef 100644
--- a/Azaion.Annotator/DTO/Config.cs
+++ b/Azaion.Annotator/DTO/Config.cs
@@ -22,6 +22,8 @@ public class Config
     public List<AnnotationClass> AnnotationClasses { get; set; } = [];
 
     private Dictionary<int, AnnotationClass>? _annotationClassesDict;
+
+    [JsonIgnore]
     public  Dictionary<int, AnnotationClass>  AnnotationClassesDict => _annotationClassesDict ??= AnnotationClasses.ToDictionary(x => x.Id);
 
     public WindowConfig MainWindowConfig { get; set; } = null!;
diff --git a/Azaion.Annotator/DTO/FormState.cs b/Azaion.Annotator/DTO/FormState.cs
index 765b0fa..bad09b5 100644
--- a/Azaion.Annotator/DTO/FormState.cs
+++ b/Azaion.Annotator/DTO/FormState.cs
@@ -15,7 +15,7 @@ public class FormState
     public Size CurrentVideoSize { get; set; }
     public TimeSpan CurrentVideoLength { get; set; }
 
-    public bool BackgroundShown { get; set; }
+    public TimeSpan? BackgroundTime { get; set; }
     public int CurrentVolume { get; set; } = 100;
     public ObservableCollection<AnnotationResult> AnnotationResults { get; set; } = [];
     public WindowsEnum ActiveWindow { get; set; }
diff --git a/Azaion.Annotator/DatasetExplorer.xaml.cs b/Azaion.Annotator/DatasetExplorer.xaml.cs
index bff4812..c49cdd3 100644
--- a/Azaion.Annotator/DatasetExplorer.xaml.cs
+++ b/Azaion.Annotator/DatasetExplorer.xaml.cs
@@ -47,7 +47,7 @@ public partial class DatasetExplorer
         Loaded += async (_, _) =>
         {
             AllAnnotationClasses = new ObservableCollection<AnnotationClass>(
-                new List<AnnotationClass> { new(-1, "All") }
+                new List<AnnotationClass> { new() {Id = -1, Name = "All", ShortName = "All"}}
                     .Concat(_config.AnnotationClasses));
             LvClasses.ItemsSource = AllAnnotationClasses;
 
diff --git a/Azaion.Annotator/MainWindow.xaml b/Azaion.Annotator/MainWindow.xaml
index 7bb400f..a056f6c 100644
--- a/Azaion.Annotator/MainWindow.xaml
+++ b/Azaion.Annotator/MainWindow.xaml
@@ -260,7 +260,12 @@
                             <Style TargetType="DataGridCell">
                                 <Setter Property="Background">
                                     <Setter.Value>
-                                        <SolidColorBrush Color="{Binding Path=ClassColor}"></SolidColorBrush>
+                                         <LinearGradientBrush StartPoint="0 0 " EndPoint="1 0">
+                                             <GradientStop Offset="0.3" Color="{Binding Path=ClassColor1}" />
+                                             <GradientStop Offset="0.5" Color="{Binding Path=ClassColor2}" />
+                                             <GradientStop Offset="0.8" Color="{Binding Path=ClassColor3}" />
+                                             <GradientStop Offset="0.99" Color="{Binding Path=ClassColor3}" />
+                                         </LinearGradientBrush>
                                     </Setter.Value>
                                 </Setter>
                             </Style>
diff --git a/Azaion.Annotator/MainWindow.xaml.cs b/Azaion.Annotator/MainWindow.xaml.cs
index 8b06d80..113e092 100644
--- a/Azaion.Annotator/MainWindow.xaml.cs
+++ b/Azaion.Annotator/MainWindow.xaml.cs
@@ -123,7 +123,7 @@ public partial class MainWindow
 
         ReloadFiles();
         if (_config.AnnotationClasses.Count == 0)
-            _config.AnnotationClasses.Add(new AnnotationClass(0));
+            _config.AnnotationClasses.Add(new AnnotationClass{Id = 0});
 
         AnnotationClasses = new ObservableCollection<AnnotationClass>(_config.AnnotationClasses);
         LvClasses.ItemsSource = AnnotationClasses;
@@ -299,7 +299,7 @@ public partial class MainWindow
                 if (File.Exists(imgPath))
                 {
                     Editor.Background = new ImageBrush { ImageSource = await imgPath.OpenImage() };
-                    _formState.BackgroundShown = true;
+                    _formState.BackgroundTime = time;
                     videoSize = Editor.RenderSize;
                 }
             }
diff --git a/Azaion.Annotator/MainWindowEventHandler.cs b/Azaion.Annotator/MainWindowEventHandler.cs
index e4f1ab8..dd206f2 100644
--- a/Azaion.Annotator/MainWindowEventHandler.cs
+++ b/Azaion.Annotator/MainWindowEventHandler.cs
@@ -150,10 +150,10 @@ public class MainWindowEventHandler :
                     _mediaPlayer.Pause();
                     if (!_mediaPlayer.IsPlaying)
                         _mainWindow.BlinkHelp(HelpTexts.HelpTextsDict[HelpTextEnum.AnnotationHelp]);
-                    if (_formState.BackgroundShown)
+                    if (_formState.BackgroundTime.HasValue)
                     {
                         _mainWindow.Editor.Background = new SolidColorBrush(Color.FromArgb(1, 0, 0, 0));
-                        _formState.BackgroundShown = false;
+                        _formState.BackgroundTime = null;
                     }
                     break;
                 case PlaybackControlEnum.Stop:
@@ -248,11 +248,11 @@ public class MainWindowEventHandler :
         if (_formState.CurrentMedia == null)
             return;
 
-        var time = TimeSpan.FromMilliseconds(_mediaPlayer.Time);
+        var time = _formState.BackgroundTime ?? TimeSpan.FromMilliseconds(_mediaPlayer.Time);
         var fName = _formState.GetTimeName(time);
 
         var currentAnns = _mainWindow.Editor.CurrentAnns
-            .Select(x => new YoloLabel(x.Info, _mainWindow.Editor.RenderSize, _formState.BackgroundShown ? _mainWindow.Editor.RenderSize : _formState.CurrentVideoSize))
+            .Select(x => new YoloLabel(x.Info, _mainWindow.Editor.RenderSize, _formState.BackgroundTime.HasValue ? _mainWindow.Editor.RenderSize : _formState.CurrentVideoSize))
             .ToList();
 
         await YoloLabel.WriteToFile(currentAnns, Path.Combine(_config.LabelsDirectory, $"{fName}.txt"));
@@ -267,12 +267,13 @@ public class MainWindowEventHandler :
         _mainWindow.Editor.RemoveAllAnns();
         if (isVideo)
         {
-            if (_formState.BackgroundShown)
+            if (_formState.BackgroundTime.HasValue)
             {
                 //no need to save image, it's already there, just remove background
                 _mainWindow.Editor.Background = new SolidColorBrush(Color.FromArgb(1, 0, 0, 0));
-                _formState.BackgroundShown = false;
+                _formState.BackgroundTime = null;
 
+                //next item
                 var annGrid = _mainWindow.DgAnnotations;
                 annGrid.SelectedIndex = Math.Min(annGrid.Items.Count, annGridSelectedIndex + 1);
                 _mainWindow.OpenAnnotationResult((AnnotationResult)annGrid.SelectedItem);
diff --git a/Azaion.Annotator/config.json b/Azaion.Annotator/config.json
index 8e83711..5dd0ea1 100644
--- a/Azaion.Annotator/config.json
+++ b/Azaion.Annotator/config.json
@@ -6,16 +6,17 @@
   "ResultsDirectory": "E:\\results",
   "UnknownImages": "E:\\unknown",
   "AnnotationClasses": [
-    { "Id": 0, "Name": "Броньована техніка", "Color": "#40FF0000" },
-    { "Id": 1, "Name": "Вантажівка", "Color": "#4000FF00" },
-    { "Id": 2, "Name": "Машина легкова", "Color": "#400000FF" },
-    { "Id": 3, "Name": "Артилерія", "Color": "#40FFFF00" },
-    { "Id": 4, "Name": "Тінь від техніки", "Color": "#40FF00FF" },
-    { "Id": 5, "Name": "Окопи", "Color": "#4000FFFF" },
-    { "Id": 6, "Name": "Військовий", "Color": "#40000000" },
-    { "Id": 7, "Name": "Накати", "Color": "#40800000" },
-    { "Id": 8, "Name": "Танк з захистом", "Color": "#40008000" },
-    { "Id": 9, "Name": "Дим", "Color": "#40000080" }
+    { "Id": 0, "Name": "Броньована техніка", "ShortName": "Бронь" },
+    { "Id": 1, "Name": "Вантажівка", "ShortName": "Вантаж" },
+    { "Id": 2, "Name": "Машина легкова", "ShortName": "Машина" },
+    { "Id": 3, "Name": "Артилерія", "ShortName": "Арта" },
+    { "Id": 4, "Name": "Тінь від техніки", "ShortName": "Тінь" },
+    { "Id": 5, "Name": "Окопи", "ShortName": "Окопи" },
+    { "Id": 6, "Name": "Військовий", "ShortName": "Військов" },
+    { "Id": 7, "Name": "Накати", "ShortName": "Накати" },
+    { "Id": 8, "Name": "Танк з захистом", "ShortName": "Танк захист" },
+    { "Id": 9, "Name": "Дим", "ShortName": "Дим" },
+    { "Id": 10, "Name": "Літак", "ShortName": "Літак" }
   ],
   "MainWindowConfig": {
     "WindowSize": "1920,1080",