Visualize 3 Dimensional Array

Unity Engine
1

What is the smartest concept to visualize a two dimensional array in Unity?

What I basically want to do is to have one dimension represented on the x axis, one one the y axis and the value via colour. This way I would have in HD about 1920*720 pixels of information which each can show 256 conditions.

One approach would be to generate 1920*720 instances of a one pixel gameobject and to change their colour.
On first sight this seems performance intense, but at the same time I would imagine the programming work is rather straight-forward, especially since I used Adobe Flash before.

A different approach would be to have a 1920*720 texture and draw the pixels, which most likely is easier on the performance. But I have to admit, I don’t have the slightest idea about the technical approach and am entirely unable to wrap my head around it. So far I did not find a single tutorial which explains how to change single pixels.

The whole image is supposed to get updated several times per second, but a framerate around 5 fps would most likely be enough for the purpose.

2 
Texture2D texture = new Texture2D(width, height, TextureFormat.ARGB32, false);
for (int y = 0; y < height; y++)
{
    for (int x = 0; x < width; x++)
    {
        Vector2 p = new Vector2(x + minX, y + minY);
        texture.SetPixel(x, y, GetMapColor(c, p));
    }
}
texture.filterMode = FilterMode.Point;
texture.Apply();
3

Thanks… I guess I get the direction now.

Do I use the texture in Label a onGUI or is there a less messy way to deal with it?