Rota Time Calculations And Colour Coding

I am currently working on a rota for my work. What I would like to code is that if a shift begins before 8am and finishes after 2pm it automatically deducts an hour for a lunch break. The spreadsheet currently calculates how long a shift is excluding any calculations for breaks, then checks whether that shift is a normal working day for the staff member, and returns the additional hours the staff member worked on that day. Separately, if possible I would like the spreadsheet to colour code each cell. So if a shift starts before 9am the cell fill color to be red, and if a shift begins after 1:30pm for the cell fill color to be dark red.