How to do color coded ‘Due Dates’?

Good afternoon everyone,

I am trying to do something that I cant seem to find a solution for after a ton of Googling. I work for a very large company and I am creating a SharePoint site (my first time) for my team and things are going well and I’m learning a lot. 

Here’s the scenario: I have forms that need to be filled out for our clients. We keep track of a “date received” (when the form shows up in my email from the client), then an “in process” date (when I start filling the form out), and then a “Due Date” (when the form is scheduled to be done, which is currently set for 14 days from the “In Process Date”)

Right now, I have a column for each of the 3 dates mentioned above. The “Date Received” and “In Process” dates are entered by selecting the date from the built in calendar I see when I go to “Edit Item” I have a few things I am wanting to do with the date stuff, but right now I am focused on stoplight color coding. Due Date is a calculated column that adds 14 (days) to the “In Process” date which then is calculated and displayed as the “Due Date”

What I want to do, is for the dates under “Due Date” to be green (preferably the dates and not the background, but willing to do either) when date is say 14-9 days away from the due date, then yellow or amber when 8-5 days away from the due date, and then lastly red when 4-0 days from due date and even when its past due date.

In sudo form I guess this is what I am looking to do

If “In Process” date is >= 9 days from “Due Date”

Then calculated due date = green

If <today’s date> is >= 5 days from “Due Date”

Then calculated due date = amber

If <today’s date> is <= 4 days from “Due Date” 

Then calculated due date = red

I don’t know if that muddied up the waters more, but hopefully you get the idea. Any help figuring this out would be greatly appreciated. I should not that some things, like workflow, is disabled and I don’t have access to.