This drawer brings back to Odin drawing of blue lines next to overriden properties. Based on PropertyContextMenuDrawer

PrefabOverrideDrawer.cs

using Sirenix.OdinInspector.Editor;
using Sirenix.Utilities;
using Sirenix.Utilities.Editor;
using UnityEditor;
using UnityEngine;

[DrawerPriority(0,10000,0)]
public sealed class PrefabOverrideDrawer<T> : OdinValueDrawer<T>
{
	private static readonly Color OVERRIDE_MARGIN_COLOR = new Color(0.003921569f, 0.6f, 0.9215686f, 0.75f);

	protected override bool CanDrawValueProperty(InspectorProperty property)
	{
#if ODIN_INSPECTOR_3
		return !property.IsTreeRoot && property.SupportsPrefabModifications && property.State.Enabled &&
		       property.State.Visible && property.Tree.PrefabModificationHandler.HasPrefabs &&
		       GlobalConfig<GeneralDrawerConfig>.Instance.ShowPrefabModifiedValueBar;
#else
		return base.CanDrawValueProperty(property) && property.SupportsPrefabModifications &&
		       property.Tree.PrefabModificationHandler.HasPrefabs;
#endif
	}

	/// <summary>
	/// Draws the property.
	/// </summary>
	protected override void DrawPropertyLayout(GUIContent label)
	{
		bool draw = Event.current.type == EventType.Repaint;

		bool overriden = false;
		bool childOrCollectionOverriden = false;

		if (draw)
		{
			var valueOverriden = Property.ValueEntry != null && Property.ValueEntry.ValueChangedFromPrefab;
			var childValueOverriden = false;
			var collectionChanged = false;
			
			if (!valueOverriden)
			{
				collectionChanged = Property.ValueEntry != null && (Property.ValueEntry.ListLengthChangedFromPrefab ||
				                                                    Property.ValueEntry.DictionaryChangedFromPrefab);
				
				if (!collectionChanged)
					childValueOverriden = ChildValueOverriden(Property);
			}
			
			overriden = childOrCollectionOverriden = childValueOverriden || collectionChanged;
			
#if !ODIN_INSPECTOR_3
			overriden = overriden || valueOverriden;
#endif

			if (overriden)
				GUIHelper.BeginLayoutMeasuring();
		}
		
		if (draw && childOrCollectionOverriden)
			GUIHelper.PushIsBoldLabel(true);
		
		CallNextDrawer(label);
		
		if (draw && childOrCollectionOverriden)
			GUIHelper.PopIsBoldLabel();

		if (!draw || !overriden)
			return;
		
		var rect = GUIHelper.EndLayoutMeasuring();

		var partOfCollection = Property.Parent != null && Property.Parent.ChildResolver is ICollectionResolver;
		
		if (partOfCollection)
			rect = GUIHelper.GetCurrentLayoutRect();

		GUIHelper.IndentRect(ref rect);

		GUIHelper.PushGUIEnabled(true);

		if (!partOfCollection && childOrCollectionOverriden)
			rect.height = EditorGUIUtility.singleLineHeight;
		
		rect.width = 2;
		rect.x -= 2;
		
		SirenixEditorGUI.DrawSolidRect(rect, OVERRIDE_MARGIN_COLOR);
		
		GUIHelper.PopGUIEnabled();
	}

	private static bool ChildValueOverriden(InspectorProperty property)
	{
		var children = property.Children;
		var count = children.Count;
		
		for (var index = 0; index < count; index++)
		{
			var child = children[index];
			var valueEntry = child.ValueEntry;

			if (valueEntry != null && (valueEntry.ValueChangedFromPrefab ||
			                           valueEntry.ListLengthChangedFromPrefab ||
			                           valueEntry.DictionaryChangedFromPrefab))
			{
				return true;
			}

			if (ChildValueOverriden(child))
				return true;
		}

		return false;
	}
}

Update:

• blue line is positioned according to property indent
• properly work with attributes like Space and Title

Probably is a bit more expensive.