Add white noise to entire screen

Hello,

I am creating an experiment that presents a variable number of shapes and would like to add static white noise on the entire screen, including during the inter-stimulus interval. I looked at a few other threads, including this one. There are several issues I am hoping to avoid with the approach used in that thread, such as manually writing large portions of the experiment.

My question is this: is there a way add static white noise to the entire screen after the shapes have already been displayed by injecting a few lines of code into the custom code component?

I am attaching a simplified version of the experiment to help describe what I am trying to achieve. Thank you in advance for your help.
noise_shape.psyexp (13.5 KB)
noise_shape_lastrun.py (26.3 KB)

Are any of these noise options any good?

https://run.pavlovia.org/Wake/etemp/

@wakecarter, thank you for your reply. I am sorry for the late response. Due to the notification settings, I did not know that you replied to my post.

I looked through your examples. The main problem I am having is adding noise to both the image and the grey area outside of the image. Do you know of a way to accomplish that?

Thank you!