the_new_darks

Hello, I am new to this forum and I have registered, because I am looking for information about a modification that I am trying to make to the game, it is something very "simple", I will detail it. In the example game WoW Classic or Wow ltk classic, when looting items or buying items, the new items will be highlighted. I have tried several ways to implement it in wow ltk the old client but I don't get it. Thank you and excuse my English I use a translator since I only speak Spanish.