ddd

Code:
public Texture2D Texture;
public static string TexturePath = Application.dataPath + "/color.png";

//Application.dataPath for rust is \Steam\steamapps\common\Rust\RustClient_Data\

private void Start()
{
        //Load texture
        if (File.Exists(TexturePath))
        {
            byte[] Bytes = File.ReadAllBytes(TexturePath);
            Texture = new Texture2D(200, 200);
            Texture.LoadImage(Bytes);
        }
}

public void BoxRect(float x, float y, float w, float h)
{
        if (Texture != null)
        {
            GUI.DrawTexture(new Rect(x, y, w, h), (Texture)Texture);
        }
}

public void Box(float x, float y, float w, float h, float thick)
{
        BoxRect(x, y, w, thick);
        BoxRect(x, y, thick, h);
        BoxRect(x + w, y, thick, h);
        BoxRect(x, y + h, w + thick, thick);
}

private void OnGUI()
{
        Box(100.0f, 100.0f, 50.0f, 100.0f);
}