30, 60, 90 Day Conditional Formatting

I am stumped on an active excel I am trying to create for a training tracker. I have attached an example of what I am trying to accomplish. I want to insert an initial date and have it auto populate an annual expiration date and at the same time have the expiration column highlight depending on 30,60,90 days prior to expiration.

30= Red
60=Amber
90=Yellow
>90=Green
I have tried many equations in conditional formatting with no success. Can someone please help me out? Thank you

SSG Cunningham
Combat Medic
US Army