Detect event by motion/image - Help

[Zarqua]

Hi.

Im trying to manipulate a event happening in a game. The event is a fishing script, where a vertical line slides from side to side and my goal is to detect when the vertical line is over the green area and then use pyautogui to press a key to complete the task. But Im fairly new to python and Im not sure how to grab this on. I have looked into cv2 but not sure if thats the right thing to start out with?

Heres a picture of what im talking about

Sidenote: the area with green, yellow and red changes from time to time after each event. So it cant be manipulated with simple macroing


Thanks in advance