If you want "3x3 colored image", you would need 6x6 of the bayer filter pixels.

Each RGB pixel would be 2x2 grid of

``` G R B G ```

So G appears twice as many as other colors (this is mostly the same for both the screen and sensor technology).

There are different ways to do the color filter layouts for screens and sensors (Fuji X-Trans have different layout, for example).

This depends on the camera and the sensor's bayer filter [0]. For example the quad bayer uses a 4x4 like:

    G G R R
    G G R R
    B B G G
    B B G G

In the example ("let's color each pixel ...") the layout is:

  R G
  G B