How to get pixels from a website quickly with python 3

(This is my first time using stackoverflow so bear with me)

I am making a program that will play a perfect snake game, but I need to tell the program when a snake reaches a certain space on the board so I can tell it to change directions. I haven't made any headway on this because I don't know where to start.

I need to read specific pixels on the screen and see when they change colors. (when playing the google snake game specifically) But I don't know how to do this and the one possible solution I have found would only work with python 2. Is there any way to do this quickly in python 3? (I don't have any idea how to do this so I'm open to any solutions or directions to research).