The Editor script for the ScenePaletteSwitcher.cs (https://gist.github.com/DomDomHaas/518d60d388bc593b2ffa5975abb9172b Is only working with the ColorPalettes u3d.as/bFr extension)

ScenePaletteSwitcherInspector.cs

using System.Linq;
using System.Reflection;
using UnityEditor;
using UnityEditor.SceneManagement;
using UnityEngine;

#pragma warning disable 3009

namespace MrWhaleGames.ColorPalette
{
  [CustomEditor (typeof (ScenePaletteSwitcher))]
  public class ScenePaletteSwitcherInspector : PaletteInspector
  {
    #region Fields


    private ScenePaletteSwitcher myObj;


    #endregion Fields

    #region Methods

    public void OnEnable ()
    {
      myObj = target as ScenePaletteSwitcher;
    }


    public override void OnInspectorGUI ()
    {
      DrawDefaultInspector();

      myObj = target as ScenePaletteSwitcher;

      if (myObj != null && myObj.PaletteData != null) {

        GUILayout.Space (20);

        drawColorPalette (myObj.PaletteData, true, false);

        GUILayout.Space(5);

        if (GUILayout.Button("Apply Palette to Scene")) {
          myObj.SwitchAllPalettes ();

          EditorSceneManager.SaveCurrentModifiedScenesIfUserWantsTo ();
        }
      }
    }


    #endregion Methods
  }
}