How to create an individual list for hundreds or even thousands of item within a grid system efficiently?

I am an architectural student working towards a submission in roughly 9 days, and I will greatly appreciate it if you can help me with my project.

I am currently working on a project which is inspired by this “SINGLE POINT ATTRACTOR” example provided by GENERATIVE LANDSCAPES:

I am trying to create a grid of squares, each equivalent to or corresponding to the pixels of my screen. And as the attractor hovers above each square, it will alter the colour value of the nearby squares by presumably increasing the RBG value with a designated value. The important bit is that the square needs to remember all the previous activities, so the colours only deepen as time pass and as the attractor hovers on it multiple times. I learned to create a script which could produce a list of aggregated value from here: How to detect an update/change of a number?

To make things more complicated (if you followed up till this point and hopefully I am making sense to you T.T), actually, my mouse cursor will act as the single point attractor when hovering over my screen monitor. I learned how to detect my mouse cursor position and my mouse clicking activities so I could also create python script to make sure when these activities are conducted on the squares (which, as mentioned, are equivalent to the position of screen pixels), the squares will react and create feedback of such activities through the deepening colour process.

So here’s my problem, the key to making sure the whole drawing system work:
How can you create a list for each square? This list is crucial as it creates colour attribute for each square of the grid system and will remember all the previous mouse activities that occur nearby, which alter the colour value of the square. Manually creating a list for each square will be laborious and I am sure that will not be done within weeks of time… Can anyone please help? Thanks! And apologies that I cannot upload any files at the moment because I am still working with them.

Thank you thank you thank you,

(02:04AM UK TIME)

So this cannot happen to me:

Because I will end up with thousands of them…