Capture RenderTexture pixels multiple times in one frame?

I have a script that moves a camera around many times in one frame. I need to capture 1x1 pixel color of the camera each time I move it to another predetermined point.

I am currently using a rendertexture and assumed I could pull out a single pixel from there to get what I wanted, but it seems to output the same color over and over even when the camera is looking elsewhere (dark grey).

Here is roughly what I am attempting; where have I gone wrong? Thanks!;

public RenderTexture vertexColorOutput; 
public Camera vertexCamera;

public void THEFUNCTION()
     Texture2D output;

      for (int i = 0; i < NUMBER; i++)
                 output = new Texture2D(1, 1);

                 vertexCamera.transform.position = positions*;*

vertexCamera.transform.rotation = rotations*;* = vertexColorOutput;

output.ReadPixels(new Rect(0, 0, 1, 1), 0, 0);

newColors = output.GetPixel(0, 0);
___________ = newColors; //Why are newColors all “33 33 33 255”?

Assigning texture based on the following page’s example code seemed to fix the problem.