Texture won't load from script?

I have a button that is supposed to make a cube dark blue. The texture I’m using is called darkBlue. I get no errors but when I click the dark blue button my cube doesn’t change colors. Any help would be nice.

using UnityEngine;
using System.Collections;



public class Color : MonoBehaviour 
{
    public Color instance;
    public string CurrentMenu;

    public GUIStyle MenuLabelGUIStyle;
    public GUIStyle colorBlue;
    public GUIStyle colorBlueL;
    public GUIStyle colorGreen;
    public GUIStyle colorGreenL;
    public GUIStyle colorPink;
    public GUIStyle colorRed;
    public GUIStyle colorYellow;
    public GUIStyle colorPurple;
    public GUIStyle colorOrange;
    public GUIStyle colorBrown;
    public bool isChosen = false;
    public float timescale = 1.0f;
    private Texture2D darkBlue;

	// Use this for initialization
	void Start () 
    {
        instance = this;
        CurrentMenu = "choColor";
        darkBlue = (Texture2D)Resources.Load("darkBlue.jpg");
	}

    void OnGUI()
    {
        if (CurrentMenu == "choColor")
            Menu_choColor();
    }
	
	// Update is called once per frame
    public void NavigateTo(string nextmenu)
    {
        CurrentMenu = nextmenu;
    }

    private void Menu_choColor()
    {
        if (isChosen == false)
        {
            GUI.Box(new Rect(10, 10, 200, 50), "Choose Your Cube Color", MenuLabelGUIStyle);
            GUI.Box(new Rect(0, 0, Screen.width, Screen.height), "");

            Time.timeScale = 0.0f;

            if (GUI.Button(new Rect(10, 130, 50, 50), "", colorBlue))
            {
                isChosen = true;
                Time.timeScale = 1.0f;
                gameObject.renderer.material.mainTexture = darkBlue;
            }
            if (GUI.Button(new Rect(70, 130, 50, 50), "", colorBlueL))
            {
                isChosen = true;
                Time.timeScale = 1.0f;
            }
            if (GUI.Button(new Rect(130, 130, 50, 50), "", colorGreen))
            {
                isChosen = true;
                Time.timeScale = 1.0f;
            }
            if (GUI.Button(new Rect(190, 130, 50, 50), "", colorGreenL))
            {
                isChosen = true;
                Time.timeScale = 1.0f;
            }
            if (GUI.Button(new Rect(250, 130, 50, 50), "", colorPink))
            {
                isChosen = true;
                Time.timeScale = 1.0f;
            }
            if (GUI.Button(new Rect(10, 200, 50, 50), "", colorPurple))
            {
                isChosen = true;
                Time.timeScale = 1.0f;
            }
            if (GUI.Button(new Rect(70, 200, 50, 50), "", colorRed))
            {
                isChosen = true;
                Time.timeScale = 1.0f;
            }
            if (GUI.Button(new Rect(130, 200, 50, 50), "", colorYellow))
            {
                isChosen = true;
                Time.timeScale = 1.0f;
            }
            if (GUI.Button(new Rect(190, 200, 50, 50), "", colorOrange))
            {
                isChosen = true;
                Time.timeScale = 1.0f;
            }
            if (GUI.Button(new Rect(250, 200, 50, 50), "", colorBrown))
            {
                isChosen = true;
                Time.timeScale = 1.0f;
            }
        }
    }
}

Do you have the file stored in the resources folder?

Yes

remove the “.jpg” and it should work, when using Resources.Load you should not use file endings.

Thank you so much! I was trying to get that to work for so long.