Categorizing practice question scores to prioritize studying?

So when I do EOC questions (both cfa textbook + schweser) I keep track of my ‘first time’ scores. I want to do this so in the end i can look at my percentages in excel and know which areas need the most focus for ‘second round’ revision. What are some appropriate ranges? I was thinking something like this

less than 50% = red zone (fubar)

50-60% = orange zone (danger)

60-70% = yellow zone (trouble)

70-80% = green zone (safe)

>80% = blue zone (expert)