Assign image color values to multiple primitives

Hi! I have a problem with assigning color information from an image to a grid of primitives. I want to rebuild the image with primitives to use the third dimension for storing information. It will be for data vis purposes.

// Error-Log: NullReferenceException: Object reference not set to an instance of an object DrawPrimitives.Start () (at Assets/nuilab/Scripts/DrawPrimitives.cs:13)

I am relatively new to Unity, C# and coding in general. I handled NullReferenceExeptions by myself until now. I do not find the problem. I hope that someone can lend me his or her eyes to track the issue.

Here is the first script which grabs the color information:

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 
 public class GetTextureColors: MonoBehaviour
 {
     public Texture2D Tex;
     public int skip = 10;
 
     Color[] AllColors;
 
     //-------------------------------------------------------------------
     void Start()
     {
         List<Color> ListOfColors = new List<Color>();
 
         for (int x = 0; x < Tex.width; x += skip)
         {
             for (int z = 0; z < Tex.height; z++)
             {
                 int currentPixel = x + z * Tex.width;
                 Color currentColor = Tex.GetPixel(x, z);
                 ListOfColors.Add(currentColor);
             }
         }
         AllColors = ListOfColors.ToArray();
     }
 
     //-------------------------------------------------------------------
     public Color[] GetColors()
     {
         return AllColors;
     }
 }

Here is the second script that builds all primitives:

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 
 public class DrawPrimitives: MonoBehaviour {
 
     GetTextureColors GetTextureColorsScript;
     Texture2D Texture;
     Color[] currentColor;
     //-------------------------------------------------------------------
     void Start()
     {
         currentColor = GetTextureColorsScript.GetColors();
         GetTextureColorsScript = GetComponent<ChangeTexture>();
         Texture = GetTextureColorsScript.Tex;
 
         GeneratePrimitives();
     }
 
     //-------------------------------------------------------------------
     void GeneratePrimitives()
     {
         int skip = ChangeTextureScript.skip;
         for (int x = 0; x < Texture.width; x += skip)
         {
             for (int z = 0; z < Texture.height; z += skip)
             {
                 int currentPixel = x + z * Texture.width;

                 Vector3 vertex = new Vector3(x * 0.1f, 0, z * 0.1f);

                 GameObject Point = GameObject.CreatePrimitive(PrimitiveType.Cube);
                 Point.transform.position = vertex;
                 Point.transform.localScale = new Vector3(0.5f, 0.5f, 0.5f);

                 Renderer rend = GetComponent<Renderer>();
                 rend.sharedMaterial.shader = Shader.Find("Cube_Material");
                 rend.sharedMaterial.SetColor("_Color" + currentPixel.ToString(), currentColor[currentPixel]);  
             }
         }
     }
 }