UX Overhaul Part 1 (#3047)

Co-authored-by: Joseph Milazzo <joseph.v.milazzo@gmail.com>

API/Entities/AppUserCollection.cs

@@ -10,7 +10,7 @@ namespace API.Entities;
 /// <summary>
 /// Represents a Collection of Series for a given User
 /// </summary>
-public class AppUserCollection : IEntityDate
+public class AppUserCollection : IEntityDate, IHasCoverImage
 {
     public int Id { get; set; }
     public required string Title { get; set; }
@@ -23,11 +23,9 @@ public class AppUserCollection : IEntityDate
     /// Reading lists that are promoted are only done by admins
     /// </summary>
     public bool Promoted { get; set; }
-    /// <summary>
-    /// Path to the (managed) image file
-    /// </summary>
-    /// <remarks>The file is managed internally to Kavita's APPDIR</remarks>
     public string? CoverImage { get; set; }
+    public string PrimaryColor { get; set; }
+    public string SecondaryColor { get; set; }
     public bool CoverImageLocked { get; set; }
     /// <summary>
     /// The highest age rating from all Series within the collection