Let me succinctly state your aim this way:
You want to highlight in red fill color the dangerous work areas that are between the start and end work areas. Thus, you need 2 lists:
1. List of dangerous work areas, which you admitted is pre-determined and so you have no problem with that; and
2. List of work areas between the start and end, wherein my last question was anchored.
If list 2 is also pre-determined, you just have to determine the instances of list 1 in list 2 and highlight those instances in red fill color.
Back to my question, such that list 2 is not pre-determined. In such case, you have to determine it and you have to know how? Perhaps at increments of 0.1 from start.
Without list 2, there is nothing to which you can compare list 1. Consequently, there would be nothing to highlight.