Progressive Increase of Colors with Noise

Hi,

I would like to know how to make the specific colors of my effect start growing with noise from certain points in the image.

In this example below, as the screen gets darker, the levels of red gradually fill everything from specific points, with this noise effect around them. I recently learned how to achieve this effect using channel levels (I think that's how it's pronounced in English) for "color correction", but when I do that, the entire image starts to be filled. I would really like to know how to achieve this same effect with noise 

Another example, but without the noise:

Thanks for the help! 😄